4. Living modified microorganisms

Dear Colleagues,

As we approach the close of the first week of discussions, I warmly encourage you to contribute your expertise to the ongoing exchange on Living Modified (LM) Microorganisms before Monday, 28 April at 11:00 a.m. (Montreal time).

Your perspectives are essential to deepening our collective understanding of the challenges and considerations of the biological characteristics involved to conduct a robust risk assessment for LM microorganisms. We’re especially keen to hear about practical applications, such as those in bioremediation and other innovative uses of LM microorganisms.

My co-moderator and I truly value your voice in this dialogue, and we’re looking forward to your contributions that will help enrich this important conversation.

Anita Anthonysamy

Esteemed colleagues,

In contribution to discussion I would like to comment on questions 1,2 and 3:

1. The risk assessment associated with the use of living modified microorganisms obtained through modern biotechnology purposes presents the challenge of being conducted in a context where there is no consolidated, specific framework that can serve as a reference or allow for the extrapolation of previously established criteria. Additionally, this type of assessment faces the particularity that there it can be of environmental use, which has limited regulatory and methodological precedents on which to rely as a primary basis.

2. Among specific challenges worth mentioning are:

- There is a wide range of possible groups of living modified microorganisms to be considered, each with specific and diverse biological characteristics, which complicates the risk assessment process. These differences include aspects such as cell structure, reproductive mechanisms, metabolism, adaptability, survival in various environments, and their potential interactions with native microbial communities.

- The end-use process may involve the simultaneous use of more than one living modified microorganism, which requires not only an individual risk assessment for each organism, but also a comprehensive analysis of potential interactions between them. These interactions can influence both the effectiveness of the process and the ecological dynamics of the receiving environment and must therefore be considered in the environmental risk assessment.

- The assessment of geographical and temporal variables in an open system such as in the case of bioremediation involving living modified organisms represents a significant challenge for establishing clear boundaries regarding monitoring, containment, and long-term risk evaluation.

3- Issues i) and iii) may be considered of importance in relation to Living Modified Organisms. 

Regarding i), the introduction of a living modified microorganisms may alter pre-existing ecological dynamics by competing with native species, modifying trophic networks, or affecting essential symbiotic microorganisms. If the LMO exhibits adaptive advantages, it could also displace other species, thereby reducing biological diversity. Additionally, horizontal gene transfer to native microorganisms may occur, potentially resulting in the emergence of microorganisms with unforeseen metabolic capabilities, or even the development of pathogenic or toxic organisms.

On the other hand, iii) the use of living modified microorganisms carries the risk of potential unintentional transboundary dispersal. Once released into the environment, these microorganisms can move and spread through various biological mechanisms and external agents such as wind, water, wildlife, or human activities, which do not recognize geographic or jurisdictional boundaries. 

Gabriel Mutis
Colombia

Greetings Colleagues,

Below is my contribution to the discussion;

Replying to Question 1
The basis of most GMO risk assessment frameworks generally revolves around evaluating for the potential impacts on human and animal health, the environment, and in some cases socio-economic factors. The review process itself uses scientific evidence (that is, safety data from various tests); history of safe use of both the unmodified organism and the inserted genetic elements; and comparative analysis with non-GM counterparts. This becomes difficult because as much as we may have been interacting with microorganisms throughout our lives, it's difficult to measure thresholds of safe use for comparison purposes.

Replying to Question 2
Most risk assessments conclude with risk management recommendations that include post release monitoring and surveillance, with an option of a recall if need be. This proves to be a challenge especially if we're talking about bioremediation where the microorganisms are released into soil or water.

Replying to Question 3
(i) Most microorganisms have the ability to spread and multiply very quickly. The dynamics of their multiplication can also change dramatically with a slight change of environmental conditions such as temperature, moisture, salinity, etc. How are risk assessors to predict how GM microorganisms might behave when introduced into a new habitat, whether intentionally or accidentally?
(ii) There's always potential for accidental introduction to the environment. And the fact that a microorganism accidental introduction may not be detected until it has spread too much complicates the issue further. There's also the possibility of horizontal transfer of modified genes to native microbes. It is difficult to accurately predict the ways in which this could potentially alter the existing microbial communities.
(iii) Depending on the particular microorganism, there's a possibility to disseminate it across national borders either intentionally or accidentally.

Hello All,

Thank you very much to the Secretariat, and the moderators for these discussions. My name is Dr Eva Sirinathsinghji and I am a biosafety researcher, working with Third World Network. My training was in genetic engineering for human neurodegenerative disease models and have since spent the last 12 years researching biosafety considerations of genetic technologies.

It is my view that the increasing focus on LM microorganisms (including microalgae related to the other topic in the discussion) raises significant biosafety considerations that warrant urgent precautionary oversight, in recognition of the high levels of risks and uncertainties that challenge our ability to perform reliable and robust risk assessments.

3 (iv) Is the LMO already, or are likely to be, commercialized or in use somewhere in the world?

LM microorganisms are now being commercialised, e.g. the new application of genome edited soil bacteria sold as a biofertilizer by PivotBio since 2019. LM microorganisms (including viruses and microalgae), are also being proposed for a wide variety of environments (e.g. soil, livestock guts, wild animal populations, marine and fresh water ecosystems) and applications (e.g. biocontrol, biofertilizers, bioremediation, public health (e.g. self-spreading transgenic viruses), conservation/climate (e.g. in vivo editing of animal gut microbiomes). (e.g. see https://www.genewatch.org/uploads/f03c6d66a9b354535738483c1c3d49e4/gm-microorganisms-fin.pdf) This moves beyond current experience to date, with assessments focusing on a limited number of traits/crop species.

1. How does this topic potentially pose challenges to the existing risk assessment frameworks?

Microorganisms pose fundamental challenges to risk assessment due to their capacity for rapid replication, spread and persistence, and gene flow, introducing a lack of controllability and added evolutionary dimensions. This is compounded by a lack of ability to recall following release.

3 (i, ii, iii). What are the specific issues concerning this topic?

The central risk of spread and persistence raises concerns that applications may result in a form of ‘living pollution’ with unpredictable exposure and transboundary movement potential. Dispersal routes (in general) include air, leaf litter, pollen, seeds, insects, or soil-associated animals or fungi. Moreover, dispersed microorganisms have been shown to establish both transiently, and over the long-term, with even transient invaders capable of causing shifts in microbial communities (Sessitsch et al., 2023). Several pathogens have for example, been detected in both rain and snow samples, and rain is also a key reservoir for leaf (phlyosphere) microbiota, e.g., for tomatoes (Mechan Llontop et al., 2021).

Genetic elements such as antibiotic resistance genes, can spread through wastewater treatment sites and rivers (Cai et al., 2014; Mao et al., 2015; L. Zhang et al., 2024), and bacterial aerosols can spread in landfill sites (Cyprowski et al., 2019).

Food/feed and digestive microbiome applications are also relevant to unintended spread. Foods consumed by people can get contaminated with cattle gut microbes, as occurs with E.coli outbreaks, for example, from lettuce crops that have been sprayed with manure. Microbes could also be potentially transmitted via milk (Lyons et al., 2020).

Horizontal gene transfer (HGT) is also a significant risk, and is long recognised as a ‘pillar of bacterial evolution’ (Arnold et al., 2022). HGT raises the risk of transfer not only of engineered traits, but also of unintended mutations that may arise in a GM microbe. It may have a variety of implications depending on the trait transferred, the nature of the unintended mutations, and the behaviour of the transferred DNA within the context of the genome and biology of the nontarget organism and its environment, with implications for biodiversity and human health. E.g. Virulence factors, or metabolic traits may increase pathogenicity of microbes, or offer selective advantage to particular microbial species, resulting in shifts in community composition, with potential impacts on the functions that such microbiome communities mediate, e.g., the mediation of human/animal health by gut microbes (Borodovich et al., 2022; Dapa et al., 2023).

HGT hotspots include animal guts (relevant to applications targeting livestock microbiomes), as well as the plant rhizosphere. Bacterial-derived HGT has also been documented in animals e.g. in whiteflies, potentially underlying the rise of outbreaks following fertilizer treatments (Yang et al., 2024). The use of dead microbes (e.g. in food products) also does not ensure against HGT.

While measures are being designed to seek to contain spread, e.g., at the molecular level (known as ‘biological containment’), they remain under development, and will introduce more genetic modifications with their own risks and complexities (Ke et al., 2021).

Evolutionary dynamics presents additional risks of e.g. potential pathogenicity, or  zoonotic spillover. Concerns have been raised regarding the potential instability of genetic changes over time (e.g., Eckerstorfer et al., 2024). The dynamic nature of mutation and recombination events in wild global viromes (viral genomes), are speculated to play a defining role in spillover events (Apari & Földvári, 2023; Lentzos et al., 2022). A further concern is whether pests or diseases targeted for biocontrol by GM microbes will also evolve resistance (Eckerstorfer et al., 2024).

2.  What could be the specific challenges to related to this issue?

Uncertainties are increased by significant knowledge gaps that challenge the ability to sufficiently ensure against adverse impacts on biodiversity. E.g. with the application of GM viruses, knowing the limits of host species is very difficult, with the potential for spill-over events. Unintended impacts of the genetic engineering process or design may also alter host range. Spread and persistence are also dependent on various factors including fitness of the microbe, which cannot be easily tested in the lab due to environmental mediators. Such knowledge gaps and accompanying uncertainties cannot be resolved with additional risk assessment methods such as computer modelling.

The development of LM microorganisms also raises direct biosecurity concerns regarding potential dual use applications and unintended evolution of pathogens.

It is thus my view that the risks and uncertainties associated with LM microorganism applications (generated via both first generation and genome editing techniques), leaves an absence of reliable data on LM microorganisms, and thus an inadequate basis for assessing their potential risk remains. In accordance with the precautionary approach, it remains premature for LM microorganisms to be safely released into the environment.

I would also like to support the previous posts #12288 and #12293.

Thank you very much.


Apari, P., & Földvári, G. (2023). Domestication and microbiome succession may drive pathogen spillover. Frontiers in Microbiology, 14, 1102337. https://doi.org/10.3389/fmicb.2023.1102337

Arnold, B. J., Huang, I.-T., & Hanage, W. P. (2022). Horizontal gene transfer and adaptive evolution in bacteria. Nature Reviews Microbiology, 20(4), 206–218. https://doi.org/10.1038/s41579-021- 00650-4

Cyprowski, M., Ławniczek-Wałczyk, A., Gołofit-Szymczak, M., Frączek, K., Kozdrój, J., & Górny, R. L. (2019). Bacterial aerosols in a municipal landfill environment. Science of The Total Environment, 660, 288–296. https://doi.org/10.1016/j.scitotenv.2018.12.356

Eckerstorfer, M. F., Dolezel, M., Miklau, M., Greiter, A., Heissenberger, A., & Engelhard, M. (2024). Scanning the Horizon for Environmental Applications of Genetically Modified Viruses Reveals Challenges for Their Environmental Risk Assessment. International Journal of Molecular Sciences, 25(3), 1507. https://doi.org/10.3390/ijms25031507

Lentzos, F., Rybicki, E. P., Engelhard, M., Paterson, P., Sandholtz, W. A., & Reeves, R. G. (2022). Eroding norms over release of self-spreading viruses. Science, 375(6576), 31–33. https://doi.org/10.1126/science.abj5593

Lyons, K. E., Ryan, C. A., Dempsey, E. M., Ross, R. P., & Stanton, C. (2020). Breast Milk, a Source of Beneficial Microbes and Associated Benefits for Infant Health. Nutrients, 12(4), 1039. https://doi.org/10.3390/nu12041039

Mao, D., Yu, S., Rysz, M., Luo, Y., Yang, F., Li, F., Hou, J., Mu, Q., & Alvarez, P. J. J. (2015). Prevalence and proliferation of antibiotic resistance genes in two municipal wastewater treatment plants. Water Research, 85, 458–466. https://doi.org/10.1016/j.watres.2015.09.010

Mechan Llontop, M. E., Tian, L., Sharma, P., Heflin, L., Bernal-Galeano, V., Haak, D. C., Clarke, C. R., & Vinatzer, B. A. (2021). Experimental Evidence Pointing to Rain as a Reservoir of Tomato Phyllosphere Microbiota. Phytobiomes Journal, 5(4), 382–399. https://doi.org/10.1094/PBIOMES-04-21-0025-R

Sessitsch, A., Wakelin, S., Schloter, M., Maguin, E., Cernava, T., Champomier-Verges, M.-C., Charles, T. C., Cotter, P. D., Ferrocino, I., Kriaa, A., Lebre, P., Cowan, D., Lange, L., Kiran, S., Markiewicz, L., Meisner, A., Olivares, M., Sarand, I., Schelkle, B., … Kostic, T. (2023). Microbiome Interconnectedness throughout Environments with Major Consequences for Healthy People and a Healthy Planet. Microbiology and Molecular Biology Reviews, 87(3), e00212-22. https://doi.org/10.1128/mmbr.00212-22

Zhang, L., Chen, H., Gao, S., Song, Y., Zhao, Y., Tang, W., & Cui, J. (2024). Antibiotic resistance genes and mobile genetic elements in different rivers: The link with antibiotics, microbial communities, and human activities. Science of The Total Environment, 919, 170788. https://doi.org/10.1016/j.scitotenv.2024.170788

Dear colleagues,

Thank you to the Secretariat and the Moderator for this discussion. I echo the sentiments shared by my colleagues prior to this. Microorganisms are diverse in genetics, metabolism, interactions and ecological functions. GM microorganisms have been developed for various purposes including for bioremediation, carbon fixation and disease resistance, such as through virus induced gene silencing. This can sometimes include pathways not found in nature and introduces a risk of horizontal gene transfer with existing microbes in the environment with the potential spread of new traits. The microscopic size of microbes also make it challenging to contain and recall released microorganisms. Without appropriate culture conditions, that also biases the microbes traced.

As current guidelines focus primarily on higher order organisms, an effective risk assessment for GM microbes would require setting a baseline for a normal environment, composition of water and soil, taking geographic locations and microenvironments into consideration. This is further compounded by the rapid reproduction, recombination, and mutation rate of microbes which may provide the GM microorganism with a selective advantage, and result in persistence, displacement of native beneficial organisms, and evolutionary unpredictability. This might then cause a delayed impact on animal health and consequences for the feed/food chain resulting from consumption of any product derived from it.

It is important to establish a baseline community, a suitable assessment for dispersal, emergent behaviors and stability of microbial traits, characterize byproducts, antimicrobial resistance, virulence, pathogenicity and toxin production, as well as provide guidance on evaluating ecological consequences and post-monitoring period. I would also like to support previous posts #12288, #12293 and #12296.

Thank you.


Kumitaa Theva Das
Malaysia


Resources:
1. EFSA Panel on Genetically Modified Organisms (GMO). (2011). Guidance on the risk assessment of genetically modified microorganisms and their products intended for food and feed use. EFSA Journal, 9(6), 2193.
2. EFSA Scientific Committee, More, S., Bampidis, V., Benford, D., Bragard, C., Halldorsson, T., ... & Cocconcelli, P. S. (2020). Evaluation of existing guidelines for their adequacy for the microbial characterisation and environmental risk assessment of microorganisms obtained through synthetic biology. EFSA Journal, 18(10), e06263.

Dear colleagues, I would like to contribute to the question 4:

Eckerstorfer, M.F.; Dolezel, M.; Miklau, M.; Greiter, A.; Heissenberger, A.; Kastenhofer, K.; Schulz, F.; Hagen, K.; Otto, M.; Engelhard, M. Environmental Applications of GM Microorganisms: Tiny Critters Posing Huge Challenges for Risk Assessment and Governance. Int. J. Mol. Sci. 2025, 26, 3174. https://doi.org/10.3390/ijms26073174  https://www.mdpi.com/1422-0067/26/7/3174

Lee, H.; Kim, D.-U.; Son, J.; Kim, S.-B.; Ka, J.-O. Environmental Risk Assessment of Living Modified Microorganisms (LMM) on the Indigenous Microbial Community. Sustainability 2020, 12, 5566. https://doi.org/10.3390/su12145566

Alexandra Lensch, Hanna Abbas Lindfors, Elke Duwenig, Tobias Fleischmann, Carsten Hjort, Sirpa O. Kärenlampi, Lucie McMurtry, Emily-Denise Melton, Mikael Rørdam Andersen, Ryan Skinner, Markus Wyss, Richard van Kranenburg. Safety aspects of microorganisms deliberately released into the environment. EFB Bioeconomy Journal, Volume 4, 2024. https://doi.org/10.1016/j.bioeco.2023.100061.

Thanks for the interesting discussion and resources provided,
Galina

Dear colleagues,

My name is Anita Greiter. I am an ecologist working at the Environment Agency Austria on biosafety issues since 2009. I am also BCH National Focal Point for Austria.

Concerning the questions raised I would like to draw your attention to a recently published paper by Eckerstorfer et al. (2025) regarding genetically modified microorganisms (GMM). Based on two case studies the authors discuss risk assessment considerations including challenges and open issues. In addition, sustainability issues are addressed as well as issues raised by technology assessment.

Relating to question 1, a number of open issues for the risk assessment of GMMs are raised by Eckerstorfer et al. (2025). They conclude that GMM applications pose challenges e.g. regarding risk assessment approaches, and the assessment of long-term effects. Thus, further work on this topic GMM is very important.

Regaring question 2 and 3: Challenges include e.g. the size of GMMs, complicating the detection in the environment and the assessment and monitoring of their survival after release, taxonomic identification, short generation times, high mobility, and the possibility for spread and dispersal in soil and aquatic environments. Other challenges (naming only a few) are the complex interactions in the environment, and the availability of standardised methods for the assessment of genetic stability, fluidity, fitness and persistence. 
GMMs may impact different ecosystem functions and species  (including animals and their microbiomes). There is limited knowledge regarding the complex ecological interactions in the receiving environments and the fluctuations in the respective microbial communities.

Regarding the last question I also would like to refer to a horizon scanning exercise by Miklau et al. (2024).

With highlighting a few aspects in the complex field of GMMs I am looking forward to the discussion.
Thank you very much
Anita


Eckerstorfer, M.F.; Dolezel, M.; Miklau, M.; Greiter, A.; Heissenberger, A.; Kastenhofer, K.; Schulz, F.; Hagen, K.; Otto, M.; Engelhard, M. Environmental Applications of GM Microorganisms: Tiny Critters Posing Huge Challenges for Risk Assessment and Governance. Int. J. Mol. Sci. 2025, 26, 3174. https://doi.org/10.3390/ijms26073174 . https://www.mdpi.com/3247114

Miklau, M.; Burn, S.-J.; Eckerstorfer, M.; Dolezel, M.; Greiter, A.; Heissenberger, A.; Hörtenhuber, S.; Zollitsch, W.; Hagen, K. Horizon scanning of potential environmental applications of terrestrial animals, fish, algae and microorganisms produced by genetic modification, including the use of new genomic techniques. Front. Genome Ed. 2024, 6, 1376927 https://www.frontiersin.org/journals/genome-editing/articles/10.3389/fgeed.2024.1376927/full

Thank you Eva for this intervention. I would like to highlight your mention of biological containment. This is a concept in genetic engineering that dates to the Asilomar Conference era. It has often been invoked for containment of genetically modified plants, such as through the manipulation of chloroplasts. And as you say, it is a concept that has lacked rigorous examination.

Hurlbut, J.B. (2018) Laws of Containment: Control without Limits in the New Biology. In Gene Editing, Law, and the Environment: Life Beyond the Human (Braverman, I. ed), pp. 77-94, Routledge.

Although not on the list of items for which guidance is sought, I'd like to suggest that guidance on biological risk mitigation strategies would be a welcome addition.

Biological containment strategies are scale limited. Attenuated bacteria are the poster children of the concept, but it is now clear that their assumed fitness disadvantage is over-estimated and context-dependent. Likewise, the low frequency of escape of chloroplasts via pollen is near certainty of escape at the scale of crop monocultures.

Similarly for replication-attenuated viruses which may recover through recombination, sometimes even with viruses of fundamentally different types. (This fascinating story from 1999 I recommend for the interested: Gibbs, M.J. and Weiller, G.F. (1999) Evidence That a Plant Virus Switched Hosts to Infect a Vertebrate and Then Recombined with a Vertebrate-Infecting Virus. Proc. Natl. Acad. Sci. USA 96, 8022-8027.) There is also evidence that virus recombination frequencies are influenced by double-stranded breaks which might arise from an off-target effect of a site-directed nuclease. Martin, D.P. et al. (2011) Recombination in Eukaryotic Single Stranded DNA Viruses. Viruses
3 (9), 1699-1738.

ngā mihi,
Jack

My name is Christoph Then and I am a member of ENSSER (The European Network of Scientists for Social and Environmental Responsibility) and representing Testbiotech (http://www.testbiotch.org) in this discussion.

I  address the four questions brought forward by the moderator.

1. We agree with Miklau et al (2024) that state: “From a risk assessor’s perspective these potential applications entail a multitude of possible pathways to harm. The current limited level of experience and limited amount of available scientific information could constitute a significant challenge in the near future, for which risk assessors and competent authorities urgently need to prepare.”


2. There are several specific challenges to current risk assessment guidance and methodologies:

- what often missing are empirical data on the phenotypic characteristics of LMO micro-organisms, e. g. in regard to proliferation, horizontal gene transfer, mobility, population dynamics, potential for colonisation, persistence and spread. More specifically, "1) increased environmental survival and host colonisation, 2) increased invasiveness and, 3) increased competition in naturally evolved microbial communities due to enhanced fitness, thereby displacing beneficial microorganisms or disrupting, 4) altered metabolism, e.g. by changes in substrate utilisation opening new environmental niches; 5) altered lifestyle, e.g. by energy use (aerobic versus anaerobic) opening new environmental niches”, (EFSA 2020)  should be taken into account.
- what needs to be considered are data about changes in symbiotic microbiomes (such as those associated with fungi, lichens, plants, animals, humans, in the soil, above soil or within aquatic systems) by taking the concept of the holobiont into account;
- what should be taken into account are cumulative effects and potential interactions with other GE organisms sharing the same receiving environment; 
- also LMO microorganisms (or nucleotides) that may contaminate the fields and /or the food chain, but are not meant for food production (see for example Fraiture et al., 2024) should be taken into account;
- what needs to be defined are cut-off criteria in order to make adequate decisions if too many unknowns and uncertainties emerge (Then et al., 2020). As EFSA states (EFSA, 2020): “Even with the complete genetic information of a synthetic micro-organism, it is beyond the capacity of any existent bioinformatic analysis to fully predict the capability of a synthetic organism to survive, colonise and interact with other organisms under natural conditions, given the uncountable diversity of potential microhabitats and their temporal variability.”
- finally, the impact of (generative) AI on the future development of micro-organisms should be included (Helmy et al., 2020; Radivojević T. et al., 2020; Noshay et al., 2023);

3. In the light of the statements above made by colleagues and being aware of the the existing publications (see also below), the first three questions can be answered with yes.

On the forth question, some overview is provided for example by EFSA, 2024; Eckerstorfer et al., 2025; Miklau et al., 2024 and Vogel (2025).

In addition the following possible upcoming applications should be considered:
- Introduction of whole sets synthetic microbial communities (de Souza et al., 2020; Rubin et al., 2022; Ali et al., 2023).
- LMO microorganisms (including viruses) that may be released as plant protecting effectors, or as ‘bio-pesticides’ in and around the fields, or intended to control parasites (Huang et al., 2023; Lang et al., 2023; Lovett & Leger 2017; Lovett et al., 2019; Zhao et al., 2016; Eckerstorfer et al., 2024)
- LMO microorganisms inheriting specific systems meant to change, e. g. the characteristics of plants, animals or other microorganisms, thus involving specific vectors, (see, for example, Reeves et al., 2018), or mobile genetic elements (artificial transposons), or gene drive-like mechanisms (see, for example, patent application WO2016177682 which includes artificial mobile genetic elements).
- LMO microorganisms (or nucleotides) that may contaminate the food chain or agricultural production, without these being meant for food production or consumption (see, for example, patent application WO2016177682 which includes antibacterial GE microbes for the protection of surfaces, substrates and fluids or contaminations as found by Fraiture et al., 2024);
- LMO microorganisms meant to change the characteristics of a host (like honey bees) via paratransgenesis (Wilke et al., 2025; Leonard et al., 2020) or other specific host-related mechanisms;
- LMO microorganisms meant to change the composition of the gut microbiome (Bai et al., 2023; Ronda et al., 2019) or control bacteria on epithelial cells (WO2017112620, WO2017087909), which may have therapeutic properties, but could also contaminate or otherwise impact and change microbiomes beyond the intended purpose (WO2017087909, describing processes to control mastitis in dairy);
- LMO microorganisms, e. g.  for use in biodegradation, waste treatment and bioremediation (see for example Rafeeq et al., 2023);
- genetic engineering of associated micro-organisms or targeting non-domesticated species (such as insects; see for example Katak et al., 2023)

4. Most relevant would be future regulation that allows risk management to control and restrict the scale of releases and the exposure of the receiving environments. Even if single applications are considered as safe, their overall and combined impact may severely damage biodiversity.

Furthermore, in the face of the uncertainties that go along with these applications, ‘cut-off’ criteria are needed that allow to reject a application if there are to many unknowns to derive to reliable conclusions (Then et al., 2020).


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Bai, Xiaowu, Huang; Ziyu Duraj-Thatte; Anna M. Ebert et al (2023) Engineering the gut microbiome, Nature Reviews Bioengineering, https://doi.org/10.1038/s44222-023-00072-2

de Souza RSC, Armanhi JSL and Arruda P (2020) From Microbiome to Traits: Designing
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Eckerstorfer, M.F.; Dolezel, M.; Miklau, M.; Greiter, A.; Heissenberger, A.; Kastenhofer, K.;
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EFSA (2024) Scientific Opinion on New developments in biotechnology applied to microorganisms, draft for public consultation, https://connect.efsa.europa.eu/RM/s/publicconsultation2/a0lTk000000C3VB/pc0848

Fraiture M-A., Gobbo A., Guillitte C., Marchesi U., Verginelli D, De Greve J., D'aes J., Vanneste K., Papazova N., Roosens N.H.C (2024) Pilot market surveillance of GMM contaminations in alpha-amylase food enzyme products: A detection strategy strengthened by a newly developed qPCR method targeting a GM Bacillus licheniformis producing alpha-amylase, Food Chemistry: Molecular Sciences, Volume 8, 100186, ISSN 2666-5662, https://doi.org/10.1016/j.fochms.2023.100186.

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Dear participants, it has been a pleasure to read the diverse perspectives from around the world, each with unique priorities and expectations, yet united in the ambition to advance the CBD objectives and leverage biotechnological applications.

I am Patrick Rüdelsheim, Belgian, holding a PhD in Biology and lecturing at the University of Ghent and the University of Antwerp. My main professional activity is assisting researchers and developers in risk assessment and management of biologicals as well as compliance with biotechnology regulations.

We are actively engaged in bioremediation projects that investigate a diverse array of microorganisms. These projects encompass both single species and consortia, including naturally occurring organisms as well as those genetically modified through advanced techniques. In some instances, this involves reintroducing evolved strains back into their native habitats, while in other cases, it entails transplanting microbial communities into entirely new environments.

The discussions in this forum focus on the impacts of Living Modified (LM) microorganisms. However, there seems to be a significant lack of interest in evaluating the consequences of releasing so-called natural strains, whether they are single species or consortia, for bioremediation purposes. Despite this, many of the potential issues highlighted in other contributions could also be relevant to these scenarios. The absence of experience in risk assessment for introducing non-modified strains results in a lack of a reference framework for evaluating the introduction of LM microorganisms. While some may view this as a gap that needs to be addressed before releases can be properly evaluated, it also raises the question of why LM microorganisms require a more stringent approach.

I look forward to the continuation of this and upcoming exchanges,

Patrick

Living Modified Microorganisms (LMMs) — encompassing genetically modified bacteria, fungi, archaea, viruses, and synthetic biological constructs — are engineered to enhance industrial production, remediate polluted environments, protect crops, or treat human diseases. 
As LMMs are increasingly developed for open-environment applications, biosafety concerns arise from their unpredictable ecological behavior, capacity for horizontal gene transfer (HGT), and evolutionary adaptability. 
These characteristics challenge the robustness of existing risk assessment frameworks, many of which were designed with terrestrial plants or vertebrates in mind.
1. How does this topic potentially pose challenges to the existing risk assessment frameworks, guidance, and methodologies?
Challenges:
- Microscopic Ubiquity and Persistence: 
  Microorganisms exist across all ecosystems — soil, oceans, atmosphere — making tracking and recall nearly impossible once LMMs are released.
- High Rates of Mutation and Evolution: 
  LMMs can mutate and evolve rapidly, altering traits over ecological timescales, challenging static, one-time risk assessments (Keeling et al., 2021).
- Horizontal Gene Transfer Beyond Predictable Hosts: 
  HGT enables LMM genetic material to transfer into unrelated environmental microbes, amplifying unintended impacts across entire microbiomes (Schönknecht et al., 2013).
- Disruption of Microbial Community Networks: 
  LMMs could disturb critical microbiome functions, such as nitrogen cycling, decomposition, or symbioses with plants and animals (Singh et al., 2016).
- Cumulative and Synergistic Risks: 
  Interaction of multiple modified organisms in the same ecosystem could lead to cumulative ecological stresses that existing frameworks poorly address.
- Difficulty in Modeling Environmental Behavior: 
  Predictive models for LMM dispersal, persistence, or interaction with native biota are currently limited by gaps in microbial ecology (Redford et al., 2019).
- Invisible Spread and Cryptic Invasions: 
  LMMs can silently integrate into ecosystems without visible impacts for years — delaying detection until effects become severe (Thomsen & Willerslev, 2015).
- Unanticipated Host-Pathogen Dynamics: 
  Synthetic constructs introduced into microbial genomes could result in unexpected pathogenicity or virulence shifts in environmental or host-associated microbiomes (Fu et al., 2020).
- Global Transboundary Dissemination: 
  Microorganisms naturally cross political borders through air and water currents — raising issues of international liability, governance, and enforcement (UNEP, 2021).
- Ambiguity in Regulatory Definitions: 
  Some LMMs, especially those created through CRISPR or synthetic biology, blur the lines between 'natural' and 'modified', complicating risk categorization and regulatory oversight (OECD, 2022).
- Ethical, Cultural, and Societal Concerns: 
  Indigenous peoples and local communities, whose cultures are deeply tied to ecosystem integrity, may experience disproportionate risks from ecosystem disruptions caused by invisible microbial changes (Redford et al., 2019).

2. What could be the specific challenges related to this issue?
- Gene Transfer and Emergence of New Traits: 
  Novel genetic material could confer selective advantages to environmental microbes, creating new invasive strains or super-resilient organisms.
- Amplification of Antimicrobial Resistance (AMR): 
  LMMs containing resistance markers or unintended resistance traits could exacerbate the global AMR crisis.
- Loss of Microbial Diversity and Resilience: 
  Introduction of dominant engineered strains could cause a decline in indigenous microbial diversity, undermining ecosystem resilience to climate change or other stresses.
- Impediments to Monitoring and Control: 
  Standard surveillance methods often fail to distinguish engineered organisms once they become integrated into environmental gene pools.
- Jurisdictional Gaps and Asymmetric Capacities: 
  Some countries may lack the technical capacity to monitor or regulate LMM activities, creating global asymmetries in biosafety protection.

3. Specific Issues Concerning LMMs

(i) Potential to Cause Serious or Irreversible Adverse Effects on Biodiversity
Yes. 
- Disruption of soil, aquatic, and atmospheric microbiomes could degrade vital ecosystem services, such as nutrient cycling, water purification, and carbon sequestration.
- Irreversible changes in microbiome structure could alter evolutionary pathways of many organisms relying on microbial symbioses.
- Indigenous communities relying on stable ecosystems for agriculture, fishing, or medicinal resources could be disproportionately harmed.
(ii) Potential for Introduction into the Environment
Yes. 
- Deliberate introductions occur in bioremediation, pest control, and agriculture.
- Accidental introductions from laboratories, fermenters, or containment breaches are highly plausible.
(iii) Potential for Dissemination Across National Borders
Yes. 
- Atmospheric, aquatic, and terrestrial pathways allow rapid and often undetectable transboundary movement of microorganisms.
(iv) Commercialization or Current Use
Yes, rapidly expanding. 
- Engineered microbes are already in commercial use:
  - GM bacteria in industrial bioproduction (e.g., enzymes, pharmaceuticals).
  - Modified yeast strains for biofuel and food production.
  - Engineered cyanobacteria for carbon capture.
  - Research on engineered soil and gut microbiomes is progressing toward clinical and agricultural applications.

4. Are there existing resources on similar issues that can address this issue or resources that could be adapted to address this need?

Key Updated Resources:
- ISO 23436 (2021):     Biotechnology — Guidelines for Containment and Control of Microorganisms. 
  - Provides updated international best practices for physical and biological containment, applicable to laboratory and industrial contexts.
- OECD (2022):   Recombinant DNA Safety Considerations for Microorganisms. 
  - Updated discussions reflecting new synthetic biology constructs.

- UNEP (2021):   Frontiers in Synthetic Biology. 
  - Focuses on environmental opportunities and challenges of synthetic microorganisms.

- Recent Research Contributions: 
  - Keeling et al. (2021): Functional diversity of marine microbial life. 
  - Redford et al. (2019): Synthetic biology and conservation risks. 
  - Fu et al. (2020): Advances in microalgal and microbial biotechnology. 
  - Schönknecht et al. (2013): Horizontal gene transfer shaping microbial evolution. 
  - Thomsen & Willerslev (2015): eDNA detection in microbial ecology.

Conclusion

Living Modified Microorganisms (LMMs) represent a profound new frontier in biotechnology, offering tremendous opportunities but also posing unprecedented biosafety, ecological, and societal challenges. 
Their invisibility, mobility, high evolutionary potential, and interaction with complex microbiomes demand urgent enhancement of risk assessment methodologies, post-release monitoring systems, and international cooperation frameworks. 
The future of LMM governance must embrace dynamic, adaptive approaches that anticipate evolutionary and ecological uncertainties — ensuring that innovation proceeds safely, ethically, and sustainably.

References
- ISO 23436 (2021). Biotechnology — Guidelines for Containment and Control of Microorganisms. Geneva: International Organization for Standardization. 
- Keeling, P.J., et al. (2021). The Marine Microbial Eukaryote Transcriptome Sequencing Project. Current Biology, 31(15), R906-R909. 
- Redford, K.H., et al. (2019). Genetic Frontiers for Conservation: Synthetic Biology and Biodiversity. Science, 364(6437), eaaw3792. 
- Fu, W., et al. (2020). Advances in Microalgal Research and Engineering Development. Nature Biotechnology, 38(5), 512–515. 
- Schönknecht, G., et al. (2013). Gene Transfer from Bacteria and Archaea Facilitated Evolution of an Extremophile. Science, 339(6124), 1207–1210. 
- Thomsen, P.F., & Willerslev, E. (2015). Environmental DNA for Biodiversity Monitoring. Biological Conservation, 183, 4-18. 
- UNEP (2021). Frontiers in Synthetic Biology: Environmental Opportunities and Challenges. Nairobi: UNEP.

Ossama AbdelKawy
Egypt National Focal Point of the Cartagena Protocol
Microbiology and Biotechnology Professor, British University in Egypt
Research Professor, Egyptian Atomic Energy Authority
Science Advisor, Egyptian Ministry of Environment

Dear colleagues--

I am Bob Friedman, with the J. Craig Venter Institute, a genomics and synthetic biology research institute in the United States.  My thanks to our moderator for guiding this session and to all the participants for their perspectives.

I will start with question 4, existing resources.  Several useful synthesis documents by European researchers have been identified by other participants, in particular, three reports by EFSA scientific panels in 2011, 2020, and 2024.  I will add a few from the United States that some colleagues may not be aware of. 

Chemla, Y., Sweeney, C.J., Wozniak, C.A. et al. Design and regulation of engineered bacteria for environmental release. Nat Microbiol 10, 281–300 (2025).  This paper includes recommendations to the synthetic biology community for engineering strategies to help improve performance, control persistence and reduce risk. The paper is behind a paywall but here is a shareable link: https://rdcu.be/ejtg7.  The supplementary information is also quite useful as it includes tables of published environmental release studies using engineered bacteria in both the US and other countries between 1985 and 2023) Supplementary information here: https://static-content.springer.com/esm/art%3A10.1038%2Fs41564-024-01918-0/MediaObjects/41564_2024_1918_MOESM1_ESM.pdf

A policy-oriented articulation of some of the challenges that need to be addressed in the context of the US regulatory framework is available in Caltech’s Linde Center for Science, Society, and Policy report on Engineered Microbes for Environmental Release: https://authors.library.caltech.edu/records/hb9x2-t0n76  This report makes a number of recommendations for how US policymakers can take steps forward to better assess and regulation genetically modified micro-organisms, including funding additional research, establishing testing sites that can be used to provide better data and understanding, and aggregating available data in a more accessible way.  The report is the result, in part, of a workshop held last year on this topic.

Finally, a 2021 workshop report from the research office of the US Environmental Protection Agency addresses question 1: What are the “challenges posed by engineered microbes to existing risk assessment frameworks, guidance and methodologies?” And importantly, “do solutions exist?” The challenges identified by the report are not to the risk assessment framework itself, rather from research and data needs in three areas: 1) empirical experiments and monitoring, 2) models and reference databases, and 3) research capacity (staff and infrastructure). These research needs were identified separately for four categories: engineered microbes intended for widespread open uses, such as biofertilizers and bioremediation; engineered microbes intended for semi-contained use, e.g., algae ponds, biomining, and biosensors; and two categories of biopesticides.  “Research Needs for Novel Engineered Microbes and Biopesticides Intended for Open Release into the Environment”, EPA/600/R-22/109, is available here: https://www.researchgate.net/publication/369062634_Research_Needs_for_Novel_Engineered_Microbes_and_Biopesticides_Intended_for_Open_Release_into_the_Environment

Regards to all,
Bob

Dear colleagues,

Regarding question 3.iv, the European Food Safety Authority (EFSA) published in 2023 a horizon scanning on microorganisms and their products obtained by new developments in biotechnology which is available here: https://www.efsa.europa.eu/en/supporting/pub/en-8503. 35 microorganisms were identified as being developed or commercialised, 11 were bacteria, 22 yeasts, one fungal endophyte, and one microalga. 8 of them are already commercialized , 9 are published in patent applications, and 18 are under development.

Regarding question 4, EFSA has published in 2024 a scientific opinion on New developments in biotechnology applied to microorganisms (http://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2024.8895). In its opinion EFSA looked at identifying novel potential hazards and risks that new developments in biotechnology applied to microorganisms could pose for humans, animals and the environment, determining whether the existing guidelines for risk assessment of genetically modified microorganisms are applicable, fully or partially, and sufficient to risk assess new developments in biotechnology applied to microorganisms and in case existing guidelines for risk assessment are considered not applicable, partially applicable or not sufficient, to identify on which aspects existing guidelines should be updated, adapted or complemented.

Best regards,
Alexandre

POSTED ON BEHALF OF MR. KAMAL KUMAR RAI, Nepal Indigenous Biodiversity Forum (NIBF), Indigenous Knowledge and Peoples Network Society for Wetland Biodiversity Conservation Nepal
******

On the behalf of Indigenous Peoples and local communities, with respectful I am smoothly going through the open ended online forum discussion, thank you so much for the five important points, the potential and adverse impacts of LMO micro-organism, algagealgal biology, algal ecology, agrobiodiversity, fishes in native and for biodiversity. That affects into indigenous food and health systems of IPLCs will have more negative impacts to  women, youth, and persons with disabilities.

There are many beneficial microbes in Nature, Indigenous lands, waters and territories that are used by Indigenous Peoples, local communities, women based in traditional knowledge, innovations and practices enline their customs, culture and reciprocal relationship with Mother Earth and Nature.  Similarly,  Algae one of the important sources for Indigenous Peoples and local communities. They are familiar with the algal ecology and biology, fish and other wild species and their interaction in the ecosystem. The tangible and intangible connection, socio-economic, culture and ethical and diverse values of Indigenous Peoples, local communities, women and knowledge systems with these subject matter are crucially important to recognise and respect Indigenous conservation and customary sustainable use, ensuring full and effective participation at all, non-state actors. 

A clear guidance, guidelines, clear mechanism and a precautionary approach inline Article 26 of Cartagena Protocol on Biosafety, Article 8(g), 8(j) and 10 of the Convention and other voluntary guidelines under CBD.    

Thanks with regards
Kamal Kumar Rai
IPLC

Again, thank you to Ms. Anthonysamy and to the CBD Secretariat for providing this opportunity.

The very first LMOs were microorganisms.  Since 1973 we have been accumulating knowledge and experience with this kind of organism, primarily for basic scientific research but also in commerce for production of food and medicine.  It has been pointed out that microorganisms have fascinating and complex biology, different from plants and animals.  What has been less often expressed is how these differences are reflected in risk assessment frameworks and how (or if) further guidance might improve those frameworks. 

I would strongly agree with post #12332 from Robert Freidman that evaluation of the needs for risk assessment of LMO microorganisms have concluded that the framework is adequate, but that research to develop knowledge to inform case specific assessments may be beneficial.  This suggests that additional guidance is unlikely to provide value.

I would also be remiss not to point out that the comments of Patrick Rudelsheim in #12317 are very relevant to the discussion. Many of the posts here neglect to place LMO microorganisms in the context of our use of non-LMO microorganisms.  While we may collectively agree that genetic modification requires additional scrutiny, we should be considering any risks in the contexts of the risks posed by unmodified microorganisms - as instructed in paragraph 5 of Annex III to the Cartagena Protocol.

Kind Regards,
Andrew Roberts, PhD
Agriculture & Food Systems Institute

Dear colleagues,
My name is Anastasia Matthies and I am employed at German Federal Office of Consumer Protection and Food Safety (BVL), where I am responsible for the risk assessment of LMOs. Firstly, I would like to express my gratitude to the moderators and all participants for the interesting and informative discussion

4. Are there existing resources on similar issues that can address this issue or resources that could be adapted to address this need?

Echoing the posts #12343, #12345 it is important to note that there are already some reference frameworks, guidelines and methodologies for modified microorganisms. The use of existing materials rather than the creation of additional resources should be encouraged. I would also like to refer to the activities of the EFSA in relation to the risk assessment of microorganisms. The EFSA is currently preparing new, updated guidelines for microorganisms. It will cover microorganisms, viruses, fungi and microalgae in the food and feed chain, including agronomic applications. Environmental risk assessment will account for a large part of the guidance and enables a case-specific, evidence-based assessment.

https://connect.efsa.europa.eu/RM/s/consultations/publicconsultation2/a0lTk0000035F1V/pc1221

Best regards,

Anastasia Matthies

Dear participants,

My name is Luciana Ambrozevicius, I´m a regulator and a risk assessor at the Brazilian Biosafety Commission. Thank you for the opportunity to participate in the on line forum. For the proposed topic “LM microorganisms” I would like to make the following considerations regarding the criteria for new topics established in the annex I to decision CP-9/13:

1. How does this topic potentially pose challenges to the existing risk assessment frameworks, guidance and methodologies? Do solutions exist?
As any other organism there somes features about microorganism biology including the multiplication dynamics and ecological interactions that have to be careful evaluated during RA, but there is also a vast array of experience with the RA of microorganisms used for biological control and biofertilizers that could be used to inform the RA of GM MO. Also many MO currently being developed with environmental applications are using gene editing techniques for the desired traits and in many jurisdictions are considered to be conventional MO and should be evaluated under those regulatory frameworks.


2. What could be the specific challenges to related to this issue?
3. What are the specific issues concerning this topic?
There is an increase interest for the use of MO for bioremediation due to the persistence of hazardous contaminants badly affecting the globe in many ways. LM microorganisms are more powerful than naturally occurring ones and may degrade contaminants faster because they can quickly adapt to new pollutants they encounter or co-metabolize (https://www.sciencedirect.com/science/article/pii/S0045653522032441) and to accelerate evolution aiming to help climate change https://www.nature.com/articles/s41587-023-01837-1).

With this potential use of LM MO with new environmental applications it’s essential to have a deeper knowledge about microbial biology and ecology. In this case, biology documents that can be used as a reference in the RA (example - https://www.ogtr.gov.au/sites/default/files/files/2021-07/the_biology_of_nannochloropsis_oceanica_a_microalga.pdf) for target MO species will be more useful than a RA guidance. The topic “LM microorganisms” is too broad in terms of the species included and also the proposed applications and receiving environment. For such a broad topic is not possible to identify any specific challenge or issues concerning that is not covered by the case-by-case nature of the RA procedure established in the Cartagena Annex III and other international guidelines already available. The specific issues concerning LM MO such horizontal gene transfer, persistence and spread, antibiotic resistance, genetic stability, ecological interactions etc are aspects considered for many other organisms during the RA steps.

4. Are there existing resources on similar issues that can address this issue or resources that could be adapted to address this need?
There are many articles regarding specific aspects for RA of microorganisms. In general terms, there are EFSA guidance available for the RA of GMMs, including ERA for GMMs obtained through synbio, and recommendations to update this guidance for applications of environmental release. In this case we consider a duplication of work to start developing a guidance of LM MO under CPB:
- Evaluation of existing guidelines for their adequacy for the microbial characterisation and environmental risk assessment of microorganisms obtained through synthetic biology (https://doi.org/10.2903/j.efsa.2020.6263)
- Guidance on the risk assessment of genetically modified microorganisms and their products intended for food and feed use (https://doi.org/10.2903/j.efsa.2011.2193)
- New developments in biotechnology applied to microorganisms (https://doi.org/10.2903/j.efsa.2024.8895)
- Draft guidance on the characterisation and risk assessment of microorganisms used in the food chain (https://connect.efsa.europa.eu/RM/s/consultations/publicconsultation2/a0lTk0000035F1V/pc1221)
- Guidance to develop specific protection goals options for environmental risk assessment at EFSA, in relation to biodiversity and ecosystem services (https://doi.org/10.2903/j.efsa.2016.4499)
- EFSA’s scientific activities and achievements on the risk assessment of genetically modified organisms (GMOs) during its first decade of existence: looking back and ahead (https://doi.org/10.1007/s11248-013-9741-4)
- Horizon scanning on microorganisms and their products obtained by new developments in biotechnology (https://doi.org/10.2903/sp.efsa.2023.EN-8503)

Best regards,
Luciana P. Ambrozevicius

My name is Samson Simon, I work for the German Federal Agency for Nature Conservation (BfN) as a biosafety expert.
When talking about microorganisms, it is important to define the term, as in addition to bacteria, bacteriophages, viruses and microalgae can also be referred to as microorganisms. Within a horizon scanning project conducted by the Environmental Agency Austria several applications of GM microorganisms intended for environmental release were identified. A trend towards GMM with the purposes of bioremediation could be observed. Other traits of GMM comprised their use as biofertilizers, enhancing plant growth and applications for biocontrol (Miklau et al. 2016).

Lack of knowledge
As of 2016 only around 1% of soil microorganisms have been taxonomically identified (Origazzi et al. 2016). In general, there is very little knowledge on the biodiversity of microorganisms, the composition of microbial communities (microbiomes) and their role in a holistic view of ecosystems. There has not yet been a release of a genetically modified microorganism in Europe. Therefore, unlike with GM plants, the assessment of GMMs cannot be based on empirical data. There is little information available on the environmental interactions of released microorganisms, let alone genetically modified microorganisms. We need further data, including long-term studies on the spread, interaction with the various ecosystems and the role of microorganisms for a wide range of ecosystem services.

Challenges in risk assessment
Our Agency (BfN) has commissioned a project on environmental applications of GM microorganisms, conducted by the Environmental Agency Austria highlighting the main challenges for risk assessment based on two selected case studies, a GM microalgae for biofuel production and GM bacteria developed as biofertilizers (Eckerstorfer et al. 2025).

AI, SynBio and microbiology
We also see major overlaps between AI and synthetic biology. In the field of synthetic microbiology in particular, it is becoming easier to design new genomes with specially designed properties. A prominent example would be ‘mirror organisms’, for which a large group of renowned scientists has warned against creating (Adamala et al. 2025).

Best regards
Samson

References:
Adamala K.P. et al. ,Confronting risks of mirror life.Science386,1351-1353(2024).DOI:10.1126/science.ads9158

Eckerstorfer, M. F., Dolezel, M., Miklau, M., Greiter, A., Heissenberger, A., Kastenhofer, K., ... & Engelhard, M. (2025). Environmental Applications of GM Microorganisms: Tiny Critters Posing Huge Challenges for Risk Assessment and Governance. International Journal of Molecular Sciences, 26(7), 3174

Orgiazzi, A., Bardgett, R. D., and Barrios, E., Eds. 2016. Global soil biodiversity atlas. Supporting the EU Biodiversity Strategy and the Global Soil Biodiversity Initiative: pre-serving soil organism through sustainable land management practices and environ-mental policies for the protection and enhancement of ecosystem services. Global soil biodiversity initiative DOI: 10.2788/2613

Miklau, M.; Burn, S.-J.; Eckerstorfer, M.; Dolezel, M.; Greiter, A.; Heissenberger, A.; Hörtenhuber, S.; Zollitsch, W.; Hagen, K. Horizon scanning of potential environmental applications of terrestrial animals, fish, algae and microorganisms produced by genetic modification, including the use of new genomic techniques. Front. Genome Ed. 2024, 6, 1376927

Thank you to the Secretariat for hosting the online forum and the moderators for facilitating this discussion.

I am Ma. Lorelie U. Agbagala, currently Asst. Scientist at the Department of Science and Technology (DOST) in the Philippines, and National Focal Point of the BCH.

There have been a general consensus that the emergence of living modified microorganisms (LMMs), animals (LMAs), algae (LM algae), fish (LM fish), and LMOs containing stacked events undeniably introduces new biological complexities that challenge conventional risk assessment frameworks. However, I believe that it is neither practical nor scientifically necessary to develop a separate, full guidance document for each organism type or for every novel LMO that may arise in the future.
International scientific consensus — including frameworks developed by the OECD, Codex Alimentarius, Cartagena Protocol on Biosafety, and national regulators such as EFSA (European Food Safety Authority) and Health Canada — strongly supports problem formulation and case-by-case risk assessment as the most scientifically robust, efficient, and adaptive approaches to biosafety assessment.
Problem formulation allows for the identification of plausible risks based on:
• The biology of the recipient organism,
• The nature of the genetic modification,
• The intended use of the LMO,
• The characteristics of the receiving environment.
Thus, the biology of the organism, not its taxonomic category, drives risk hypotheses.
Case-by-case assessment ensures that regulatory evaluations are proportionate to the actual risk posed and responsive to diversity and novelty without overburdening the system with redundant prescriptive rules.
Moreover, global experience confirms the feasibility of this approach:
• EFSA’s risk assessment of GM animals (e.g., GM salmon) and stacked events explicitly use problem formulation within a single overarching framework.
• Health Canada's "novel trait" approach regulates products based on trait novelty, not the method of modification or the species involved.
• OECD’s biology documents for plants, fish, and microorganisms provide contextual biology to inform risk assessments without prescribing organism-specific guidance.
What is needed is:
1. Strengthening and operationalizing problem formulation across all types of LMOs
Risk assessments should consistently start with robust problem formulation that screens for potential harm based on biology and trait.
2. Development of supplementary interpretative guidance (not full new frameworks)
For complex categories (e.g., microorganisms, LM animals, LM algae), focused technical notes can highlight key considerations (e.g., potential for horizontal gene transfer in microorganisms, welfare considerations in animals, ecosystem interactions in algae and fish) while remaining within the general risk assessment structure.
3. Enhanced capacity building and practical training
Risk assessors must be trained not only in scientific methods but also in applying flexible, principle-based assessment. Training must also address emerging technologies like gene editing and synthetic biology.
4. Dynamic and iterative risk assessment processes
Incorporate mechanisms for post-approval monitoring and feedback loops, allowing real-world evidence to refine risk assessments over time.
5. Global harmonization and knowledge sharing
Leveraging experiences from OECD, FAO, UNEP, and other international biosafety initiatives ensures that the risk assessment of novel LMOs remains scientifically credible and globally consistent.

I also would like to express my agreement with posts #12351, #12357, #12336, #12317 and #12332.

Strengthening flexible, biology-based, and science-driven frameworks through problem formulation and case-by-case assessment is the most feasible, globally aligned, and scientifically sound strategy for ensuring biosafety now and in the future.

Dear Colleagues,

To contribute issue #1, and #2,

While an estimated 100+ LMM strains (e.g., Pseudomonas putida for bioremediation, Saccharomyces cerevisiae variants for industrial enzymes) have been commercially deployed worldwide under existing risk assessment protocols, the rapid emergence of synthetic biology-derived microorganisms (e.g., CRISPR-edited cyanobacteria for carbon capture, engineered phage cocktails) necessitates urgent modernization of biosafety evaluation paradigms.

Key Challenges:
Assessment Lag: Current OECD/EFSA guidelines (e.g., EFSA Journal 2023;21(7):1250) for transgenic microbes fail to address:
- Multi-trait stack organisms with edited metabolic networks
- Horizontal gene transfer risks in non-model microbiomes
- Post-release genomic stability of chassis organisms like Bacillus subtilis SYNBIOCARB
Detection Gaps: CRISPR-Cas12a-based field detection tools remain inadequate for identifying:
- Cryptic genetic circuits (e.g., quorum-sensing-controlled virulence factors)
- Unintended edits in non-coding regulatory regions
This challenge demands a dual approach: sharing detection/identification data and harmonizing PRACTICAL risk assessment methodologies/protocol/guideline with solid STANDARD and AGREEMENT to address emerging biosafety concerns

Ju Seok Lee

Dear All,

My thanks to the moderators for providing some clear questions to structure this exchange.

My name is Piet van der Meer. I am trained as a microbial ecologist and an environmental lawyer, and since 1986 I have conducted hundreds of risk assessments in regulatory context. Since the adoption of the CPB, I also provide training on risk assessment to government- and public research institutions, with the principles and methodology of Annex III as the starting- and endpoint.

Before following up on the questions posed by the moderators, it is good to note that several colleagues place their contributions in the broader context of the KM-GBF, as it is nicely summarized in the introduction to the Cartagena Protocol on Biosafety “The Protocol thus creates an enabling environment for the environmentally sound application of biotechnology, making it possible to derive maximum benefit from the potential that biotechnology has to offer, while minimizing the possible risks to the environment and to human health.”.
Given the COPMOP2024 decision CP-9/13, the opening question posed by the moderators for this debate (i.e. how LM algae, LM animals, LM fish, LM microorganisms, and LMOs containing stacked events potentially pose challenges to the existing risk assessment frameworks and methodologies), is a very pertinent one.

My response to this question is that these topics do not pose challenges to the Annex III risk assessment methodology as such. Unlike some colleagues suggest, Annex III is not primarily designed for terrestrial GMOs or for crop plants. Annex III is designed for all LMOs and can be applied to all categories LMOs, including LM algae, LM animals, LM fish, LM microorganisms, and LMOs containing stacked events.

What is true, however, is that we have more guidance on ways to collect relevant data for LM crop plants, than for LM algae et cetera. Whether or not it is worth developing additional guidance for those topics is a cost-benefit analysis for the COPMOP to make.

Regards to all,

Piet van der Meer

Dear colleagues,

I am a biologist and molecular geneticist and have focused on biosafety issues for a few decades now. 

Most has already been said in this discussion and
I want to support many of these submissions and their - from my perspective - very helpful deliberations and information. In specifics I found the contributions #12311, #12323, and #12296 raising all the major points, clarifying eloquently the challenges that risk assessment of LMMs is facing.

I would like to briefly pick out two points: that of biological containment, as highlighted by Eva Sirinathsinghji and Jack Heinemann, and that of microbiomes, highlighted by many, including Ossama AbdelKawy,  Eva  Sirinathsinghji, Anita Greiter and Christoph Then.

As Jack points out, biological containment strategies are scale limited.
Additionally, the aspect of time and of environmental conditions are also crucial in this. Given high degrees of adaptability, combined with often higher levels of sharing of DNA sequence information via horizontal gene transfer, risk assessment needs to include the scenarios and assessments of break down or break through of biological containment and their consequences.

In this context I would also like to reiterate a point I made in the context of LM algae, namely that of airborne transport of micro-algae, which is true for microorganisms as a whole (Tesson et al., 2016) (Chiu et al., 2020). Increasing drought and increasing wind can help the transport and thus the global dispersal of microorganisms, whilst
increase of severe wind and flood events capable of breaching or even destroying containment structures and facilities, will further aid the dispersal of LM microorganisms.

Thus risk assessment need to be “climate adapted”,  both in context of weather events as well as in changing ecosystems.

Regarding microbiomes, I would like to add the issue of the intentional genetic modification of plant-associated microbiomes (photo-microbiomes), where microbiomes are either genetically modified by one micro-organism at a time (so-called bottom up approach), or by “the top-down approach that involves synthetic ecology, using horizontal gene transfer to a broad range of hosts in situ and then phenotyping the microbiome.” (Ke et al, 2020)  A wider horizon scanning would be helpful to understand the extent to which different microbiomes are being investigated or targeted, to aid the understanding of the challenges of LMM risk assessments.

Concerning the topic of LM microorganisms (in the context of biosafety) as a whole, I would like to put forward and as already done by others, the recent publications of  Eckerstorfer et al. (2025) and Miklau et al. (2024).

Concluding: At present it appears that challenges are higher than can actually be resolved by risk assessment.

With kind regards,

Ricarda


References:

Chiu, C. S., Chiu, P. H., Yong, T. C., Tsai, H. P., Soong, K., Huang, H. E., & Chen, C. N. (2020). Mechanisms protect airborne green microalgae during long distance dispersal. Scientific reports, 10(1), 13984. https://doi.org/10.1038/s41598-020-71004-y

Eckerstorfer, M.F.; Dolezel, M.; Miklau, M.; Greiter, A.; Heissenberger, A.; Kastenhofer, K.; Schulz, F.; Hagen, K.; Otto, M.; Engelhard, M. Environmental Applications of GM Microorganisms: Tiny Critters Posing Huge Challenges for Risk Assessment and Governance. Int. J. Mol. Sci. 2025, 26, 3174. https://doi.org/10.3390/ijms26073174 . https://www.mdpi.com/3247114


Ke et al. (2021). Microbiome Engineering: Synthetic Biology of Plant-Associated Microbiomes in Sustainable Agriculture. Trends in Biotechnology. https://doi.org/10.1016/j.tibtech.2020.07.008


Miklau, M.; Burn, S.-J.; Eckerstorfer, M.; Dolezel, M.; Greiter, A.; Heissenberger, A.; Hörtenhuber, S.; Zollitsch, W.; Hagen, K. Horizon scanning of potential environmental applications of terrestrial animals, fish, algae and microorganisms produced by genetic modification, including the use of new genomic techniques. Front. Genome Ed. 2024, 6, 1376927 https://www.frontiersin.org/journals/genome-editing/articles/10.3389/fgeed.2024.1376927/full

Tesson, S. V. M., Skjøth, C. A., Šantl-Temkiv, T., & Löndahl, J. (2016). Airborne Microalgae: Insights, Opportunities, and Challenges. Applied and environmental microbiology, 82(7), 1978–1991. https://doi.org/10.1128/AEM.03333-15

Dear Colleagues,

First, let me thank the moderators for their work in moderating the discussion, and the CBD Secretariat for hosting it and allowing me to contribute.

My name is Andrés Frankow. I am a biologist, and I have been working in risk assessment of genetically modified organisms since 2004. I am currently part of the Coordination of Innovation and Biotechnology in the Secretariat of Agriculture, Livestock, and Fisheries.

There are regulatory frameworks with more than 20 years of implementation, along with consolidated guidelines and methodologies that specifically address the evaluation of genetically modified microorganisms, ensuring a science-based and case-by-case approach. Therefore, no significant challenges have been identified regarding this topic.
Over the years, no issues have been reported by competent authorities indicating adverse impacts on ecosystems or human health related to modified microorganisms that have been evaluated and approved under these regulatory frameworks.
Risk assessment for modified microorganisms is carried out by considering specific aspects, such as potential environmental impact and risks to human health, identifying the values to be protected, and following proper problem formulation and clear risk hypothesis development for case-by-case analysis.
This approach ensures thorough and science-based evaluations, contributing to the protection of biodiversity, human health, and the environment.

Therefore, there is no evidence to support the need for developing a specific guide on this topic.

Best regards,

Andrés

Hello everyone, in my opinion, the problem formulation approach, which relies on pathways to harm (as presented in the additional voluntary guidance materials to support case-by-case risk assessments of living modified organisms (LMOs) containing engineered gene drives), provides a robust framework for framing and informing case-by-case risk assessments of LMOs, including microorganisms. This approach is considered scientifically sound and transparent, aligning with contemporary best practices for implementing risk assessments as outlined in Annex III of the Cartagena Protocol on Biosafety. Additionally, it is sufficiently flexible to address the specificities of each LMO case (including microorganisms) under assessment. Best regards, Yann Devos

I am Ediner Fuentes-Campos, Director of Research and Development at the National Secretariat of Science, Technology and Innovation of Panama, Focal Point for the Cartagena Protocol in Panama, and Risk Assessor. I appreciate the opportunity to participate in this forum on the regulatory implications of genetically modified microorganisms (GMMs) in the context of the Cartagena Protocol.
After analyzing the shared contributions and available scientific evidence, I would like to express my position regarding the questions posed by the moderators. Annex III of the Cartagena Protocol provides a comprehensive and adaptable framework for risk assessment of genetically modified microorganisms. This framework already establishes solid principles that adequately address the particularities of GMMs through case-by-case assessment, considering their specific characteristics and the receiving environment.
I fully agree with #12357 that, although microorganisms have biological characteristics distinct from plants and animals, the current risk assessment framework of the Cartagena Protocol is sufficiently robust and flexible. As correctly noted by #12377, "Annex III is designed for all LMOs and can be applied to all categories of LMOs," including microorganisms.
I strongly endorse the position presented by #12364, who correctly points out that "the 'LM Microorganisms' topic is too broad in terms of the species included and also the proposed applications and the receiving environment. For such a broad topic, it is not possible to identify any challenge or specific issue that is not covered by the case-by-case nature of the RA procedure established in Annex III of Cartagena and in other international guidelines already available." This observation is fundamental as it underlines the sufficiency of the existing framework and the unnecessary duplication of efforts that would result from developing new specific guidelines.
The experience accumulated since 1973 with genetically modified microorganisms has generated an extensive history of safe use that we can leverage within the Protocol framework. This history demonstrates that the benefits significantly outweigh the potential risks, especially when these are evaluated case by case as established in Annex III.
Genetically modified microorganisms offer innovative solutions for urgent global challenges. As noted by #12364, there is "greater interest in the use of MO for bioremediation due to the persistence of hazardous contaminants that severely affect the world," and GMMs can "degrade contaminants faster" and "accelerate evolution with the aim of helping climate change." Additionally, GMMs are driving crucial scientific advances for the development of drugs and medicines, creating solutions for previously untreatable diseases and improving the production of bioactive compounds on an industrial scale.
I fully share the vision of #12366 when stating that "it is neither practical nor scientifically necessary to develop a separate and comprehensive guidance document for each type of organism or for each new LMO that may emerge in the future." The position on the need to "strengthen and operationalize problem formulation across all LMO types" and develop "complementary interpretive guidance" rather than new comprehensive frameworks is particularly relevant for addressing GMMs effectively and efficiently. #12366 correctly points out that "problem formulation allows the identification of plausible risks" based on the biology of the organism, the nature of the modification, the intended use, and the characteristics of the receiving environment, which ensures a scientifically sound approach without overburdening the regulatory system.
The challenges related to GMMs have been widely discussed and are well characterized in the scientific literature. These include considerations about horizontal gene transfer, persistence, antibiotic resistance, genetic stability, and ecological interactions. However, it is crucial to highlight that these challenges can be adequately addressed through: 1) The formulation of scientifically grounded risk hypotheses, 2) The rigorous application of Annex III of the Protocol, and 3) The implementation of appropriate risk management measures when necessary.
I agree with #12332 that there are numerous valuable resources that can inform our assessments. The scientific reports from EFSA mentioned by #12364 provide specific and updated guidance for GMMs, including those obtained through synthetic biology. Genetically modified microorganisms represent a viable and promising alternative with clear routes for development. The current regulatory framework, particularly the environmental risk assessment of the Cartagena Protocol, is adequate to address this technology responsibly.
I consider especially relevant the point expressed by #12366 on the need for "improved capacity development and practical training" and "dynamic and iterative risk assessment processes," as well as the importance of "global harmonization and knowledge exchange." These recommendations are much more valuable than the development of new specific guidelines and can have a significant impact on improving risk assessment capabilities globally.
In line with the positions expressed by (#12364) and (#12366), I believe that the existing frameworks, methodologies, and guidance in the context of the Cartagena Protocol are sufficient to adequately address the potential risks associated with GMMs. The experience accumulated in various countries demonstrates that the case-by-case approach established in Annex III is robust and adaptable to the particularities of these organisms. Instead of developing new guidelines, efforts should be directed towards strengthening the capacities of national regulatory agencies to effectively implement existing frameworks. This approach would allow us to leverage the potential benefits of GMMs for food, health, and scientific development, while ensuring the protection of biodiversity through rigorous and scientifically grounded risk assessments.
Respectfully,
Ediner Fuentes-Campos
Director of Research and Development
National Secretariat of Science, Technology and Innovation of Panama
Focal Point of the Cartagena Protocol in Panama

Dear Participants,

Thank you kindly for your valuable interventions and active engagement during the first week of discussions.

Week 1 of the Open-Ended Online Forum is now closed.

Please return for Week 2. The discussions will open in an hour (12 pm (noon) Montreal time).

Best regards,

The Secretariat