Scientific Program > Sessions

Regular sessions

Session: Impact of contaminants on microbial diversity and function

Chairs: Chloé Bonnineau, Natàlia Corcoll, Aurélie Cébron, and Pedro Inostroza

Keynote: Stéphane Pesce, INRAE, France

Microorganisms participate in all major biogeochemical cycles, and their diversity represents a keystone for ecosystem functioning and resilience. The adaptability of microorganisms is unequaled among living organisms. Nevertheless, similar to other groups of organisms, such as invertebrates and fish, microorganisms face increasing threats from multiple environmental stressors, particularly human-derived pollution. This session invites research on the impact of contaminants and other environmental stressors on the taxonomic and functional diversity of the microbial world, including microbial responses at the individual, population, and community levels. These investigations may involve the use of 'omics' and ‘metaomics’ tools, including genomics, transcriptomics, proteomics, and metabolomics. Laboratory and field studies dealing with microbes from soil, freshwater, marine, and human-made environments are welcome.

Keywords: diversity; functions; bioindicators; omics 

Session: Microbial roles in contaminant fate and bioremediation

Chairs: Lise Barthelmebs, Jennifer Hellal, and Dimitros Karpouzas

Keynote: Lawrence P. Wackett, University of Minnesota, USA

Microorganisms have developed a variety of metabolic adaptations and resistance mechanisms to cope with the presence of toxic elements in their environment. Microbial activity thus has a considerable impact on environmental contaminants and strongly contributes to their fate. Many microbially-driven processes may contribute to contaminant degradation, detoxification, or immobilization (e.g. sequestration, precipitation) and thus to pollution mitigation. Conversely, some others may enhance the toxicity of contaminants and their dissemination in the biosphere.

Evaluation and understanding of these processes is still challenging, in the field and the laboratory. Thus, prediction of the fate of contaminants in ecosystems remains difficult. The bioavailability and mobility of chemical contaminants in the environment, as key factors of microbial transformation of chemicals, require particular attention today. Moreover, linking available evidence of contaminant biotransformation to key microbial players involved in these processes remains mostly indirect, especially in complex ecosystems. Finally, understanding the environmental factors governing microbial activity is essential to developing efficient bioremediation strategies. In this session, we welcome original reports on all aspects of these challenging research areas, especially those involving interdisciplinary approaches at the interface of chemistry, physics, and microbiology, including modeling studies.

Keywords: bioremediation, biodegradation, biotransformation, bioavailability, immobilization, dissipation, ecological engineering 

Session: Microorganisms as a tool for environmental risk assessment

Chairs: Thomas Backhaus, Kristian Brandt, and Fabrice Martin-Laurent

Keynote: Thomas Backhaus, RWTH University Aachen, Germany and University of Gothenburg, Sweden

Microorganisms are key players of earth life: they drive important ecosystem processes and contribute substantially to global biogeochemical cycles. They exhibit a broad range of sensitivity to many toxicants and are known to be natural early warning systems that detect acute and long-term effects produced by toxic pollutants.

Until now chemical analysis remains essential to evidence contamination, however, biological indicators can provide valuable complementary information on both the impact and fate of contaminants. Microorganisms are good candidates as a tool for environmental risk assessment (ERA) since they can be found in all types of environments (water, soil…) and have a large range of sensitivity to a wide range of chemical pollutants. Innovative methods and tools for environmental risk assessment based on microorganisms have been developed in order to i/predict hazard and assess risk before the release on the market of a new active compound (a priori ERA) as well as ii/ assess, the ecotoxicological impacts of chemical residues in the environment (a posteriori ERA). Despite the recognized importance of microbial communities in supporting a range of functions and ecosystem services, microorganisms are barely considered in both a priori and a posteriori environmental risk assessment and they are typically not yet implemented in the current regulations or legislations. This session will focus on the use of microbial bioindicators/biomarkers/bioassays as well as microbial biosensors to assess the environmental risk of contaminants in various ecosystems. In particular, communications on the interest of monitoring in response to pollutant exposure the diversity and function of microbial communities using omic approaches for ERA in various ecosystems are welcome. In this session, we also intend to discuss the possible strategies to promote the use of microorganisms (at different levels of biological organization) in both a priori and a posteriori environmental risk assessment.

Keywords: bioindicators/biomarkers, biosensors, risk assessment, environmental managers, biomonitoring

Session: Antimicrobials resistance in the environment

Chairs: Anne Farewell and Johan Bengtsson-Palme

Keynote: Monika Dolejska, University of Veterinary Sciences Brno, Czech Republic 

National and international authorities are now recognizing that the environmental dimension of antimicrobial resistance must be considered when developing strategies to combat this public health menace. Antimicrobial chemicals enter the environment indirectly through human and animal waste streams and manufacturing effluents, and directly through their use in aquaculture and as pesticides in plant-based food production systems. Since these chemicals are designed to kill microorganisms (viruses, bacteria, fungi, parasites) they have potent antimicrobial activity. 

Thus, there are concerns about their impacts on microorganisms undertaking key ecosystem services. Furthermore, microorganisms in anthropogenically impacted environments may adapt by evolving or acquiring genes that confer antimicrobial resistance, increasing the reservoir of resistance genes that ultimately can be transmitted to microorganisms of human health concern. Presentations concerning any aspects of environmental development and transfer of antimicrobial resistance or antimicrobial impacts on environmental microorganisms and their functions are welcome.

Keywords: antibiotic; fungicide; antiviral, impacts, fate

Special sessions 

Session: Microbiome-aware ecotoxicology of animals

Chairs: Carmen Palacios de la Cruz and Sébastien Duperron

Keynote: Elena Gorokhova, Stockholm University, Sweden

The holobiont concept, accounting for hosts and their associated organisms, offers a new holistic perspective in Life Sciences. Because the microbiota can react to and interact with contaminants like metals, pesticides, plastics or pharmaceuticals, the relevance and impact of animal-associated microbiomes to ecotoxicology is now well-established, and necessary for understanding the relationships between organisms and their environments. We expect communications that will show how disruptions caused by contaminants can affect, or be mitigated, by microbiota associated with wildlife, modulating the health and adaptability of holobionts (either in nature or in the lab). Our sessions will inform how a "microbiome-aware ecotoxicology" can open new avenues into more effective strategies for the conservation of species and/or environments, recognizing the intricate dynamics between environmental stressors and the delicate balance of microbiomes and their hosts in populations.

Keywords: Holobiont, animal wildlife, environmental stressors, adaptation, conservation. 

Session: Occurrence, properties, fate, and microbial ecotoxicology of natural toxins  

Chairs: Louis Carles, Philipp Hess and Thomas Ostenfeld Larsen

Keynote: Hans Christian Bruun Hansen, University of Copenhagen, Denmark

Microbial ecotoxicology has developed considerably in recent years. At the interface between microbial ecology, toxicology, and biogeochemistry, this research area unravels the interactions between organic pollutants and microorganisms at different levels of organization to better understand the impact of man-made chemicals. However, anthropogenic activities are not only releasing chemicals into the environment but are also constantly modifying landscapes and impacting ecosystem functioning, leading to the development of species that produce natural toxins. This is particularly true for instance in agricultural areas with the proliferation of phytopathogenic fungi producing mycotoxins, and in aquatic environments with blooms of cyanobacteria producing cyanotoxins. 

Despite their potential impacts on microbial communities, natural toxins are rarely included in microbial ecotoxicology studies. The aim of this special session is therefore to present the current state of knowledge on the interactions between microorganisms and natural toxins and to draw potential future directions for this research area.  

In this session, we welcome communications on all aspects of occurrence, properties, and fate of natural toxins, as well as on their toxicity towards microorganisms at different organization levels and from different environments (air, water bodies, soil, animal, and plant microbiota). We also encourage submissions of communications on the capacity of microorganisms to biotransform natural toxins. 

Keywords: secondary metabolites, phycotoxins, cyanotoxins, mycotoxins