Jean-Philippe Bellenger

Jean-Philippe Bellenger is an Associate Professor at the Chemistry department at Université de Sherbrooke, Canada and the Chair-holder of the Canadian Research Chair in Boreal Biogeochemistry. His multidisciplinary research, developed at the interface of chemistry, biology and soil sciences, aims to link processes occurring at molecular level with ecosystem functions. He is an expert in biological dinitrogen (N2) fixation, trace metal biogeochemistry and trace metal acquisition by microorganisms. He notably made significant contributions to the characterization of Mo limitation of asymbiotic N2 fixation worldwide. He made important breakthroughs in the field of trace metal acquisition by discovering the role of metallophores, microbial organic ligands, for molybdenum, vanadium (and other metals) homeostasis in free living N2 fixers. He is also one of the pioneers in the description of the contribution of alternative nitrogenases to biological N2 fixation in terrestrial ecosystems. His innovative research has received several awards such as two Canadian Research Chairs (2010-2015 and 2015-2020), and the prestigious NSERC-Accelerator Award in 2016. His multidisciplinary research is developed in collaboration with researchers from broad scientific backgrounds e.g. microbiologists, civil engineers, environmental chemists and ecologists.

Currently, Pr. Bellenger is pursuing research on trace metal dynamics in multispecies biofilms and lichen symbioses.

Talk title: Why trace metals matter in environmental microbiology?
Abstract: The cycling of major nutrients, such as carbon and nitrogen, is key to ecosystems function and evolution. The biogeochemical reactions controlling the transformation and transfer of these essential nutrients (i.e. C and N) overwhelmingly rely on microbial activity. These microbial reactions are often catalysed by metalloenzymes, which use trace metals as cofactors to support their activity. Thus, trace metal bioavailability, while potentially toxic, can significantly affect the cycling of major nutrients. Our understanding of the importance of trace metal dynamics in soil on major nutrients cycling at the ecosystem scale remains very limited. Numerous metalloenzymes have several isoforms using different metal-cofactors to assume the same function. How this enzymatic diversity contributes to the response of microorgansimes to environmental stresses and to the biogeochemical cycling of major nutrients remains mostly unexplored. Using biological N2 fixation as an example, I will show how taking into account trace metal dynamics, and metalloenzyme cofactors diversity can deeply affect our understanding of ecosystems function and evolution. I will discuss the need for further research on trace metals dynamics at the soil-microorganisms interface to improve our conceptual models for interspecies interactions and symbioses establishment and function.