Richard GUILLONNEAU

I am a recently appointed assistant professor within the Biological Sciences and Biotechnology Unit (US2B, CNRS, Nantes University) since September 2023. My research aims to advance the understanding of bacterial resistance to predation by phagotrophic cells and how this resistance is interconnected with nutrient availability.

A lipid-remodeled prey is more susceptible to ciliate digestion inside the phagolysosome.
CLSM images showing GFP-labeled ΔplcP mutant of Phaeobacter sp. MED193 and acidification of
the phagolysosomes (Lysotracker, red) during predation by Uronema marinum. (Guillonneau et al., 2022)

At the moment, we are particularly interested in understanding how Vibrio cholerae, the causative agent of cholera can easily switch from rich to poor environments. Its ability to grow and divide within such distinct niches relies on precise regulation of gene expression. While intestines are nutrient-rich environments, aquatic ecosystems are generally poor in phosphorus, an essential component of the bacterial diet. To survive inorganic phosphate (Pi) starvation, many bacteria regulate genes involved in transport and metabolism of phosphorous compounds belonging to the Pho regulon by using the PhoBR two-component regulatory system. Amongst the numerous strategies under the control of the Pho regulon, bacteria can reduce their cellular demand for Pi through the substitution of membrane phospholipids with non-P-containing surrogate lipids. In my group, we are trying to understand how V. cholerae membrane remodeling affects its ability to survive in the various environments it colonises but also how this membrane switch modifies its ability to interact with phagotrophic cells.

• From September 2023, Assistant professor, UMR CNRS 6286, US2B, Nantes University
• From May 2018 to August 2023, Post-doc research fellow, University of Warwick 
• From October 2014 to May 2018, PhD-student, EA4323, MAPIEM laboratory, University of Toulon

Publications

• D. Roman, P. Meisinger, R. Guillonneau, C. C. Peng, L. K. Peltner, P. M. Jordan, V. Haensch, S. Götze, O. Wer, C. Hertweck, Y. Chen et C. Beemelmanns " Structure Revision of a Widespread Marine Sulfonolipid Class Based on Isolation and Total Synthesis" - (2024) - Angewandte Chemie
• H. Shropshire*, R. Guillonneau*, Z. Han, R. A. Jones, I. Aberdeen, S. Ahmed, I. Garcia-Romero, M. A Valvano, D.J. Scanlan, Y.Chen " Formation of glycolipids is essential for Burkholderia cenocepacia survival in vivo " - (2023) - BioRxiv - (*These authors contributed equally)
• R. Stirrup, M.A. Mausz, E. Silvano, A. Murphy, R. Guillonneau, M. Quareshy, B. Rihtman, M.A. Ferretjans, R. He J.D. Todd, D.J. Scanlan et Y. Chen " Aminolipids are essential for competitiveness in a cosmopolitan marine bacterial lineage " - (2022) - ISMEJ
• R. Guillonneau, ZJ. Teng, A. Murphy, YZ. Zhang, D.J. Scanlan et Y. Chen " Trade-offs of lipid remodeling in a marine predator-prey interaction in response to phosphorus limitation " - 2022 - PNAS
• J. Scanlan, R. Guillonneau, M.R. Cunningham, S Najmin, M.A. Mausz, A. Murphy, L. L. Murray, L. Zhang, D. Kumaresan et Y. Chen " The proteobacterial methanotroph Methylosinus trichosporium OB3b remodels membrane lipids in response to phosphate limitation " - 2022 - mBio
• ZJ. Teng, P. Wang, XL. Chen, R. Guillonneau, CY. Li, SB. Zou, J. Gong, KW. Xu, L. Han, C. Wang, D.J. Scanlan, Y.Chen et YZ. Zhang " Acrylate protects a marine bacterium from grazing by a ciliate predator " - 2021 - Nature microbiology
• A.F. Smith, E. Silvano, O. P√§uker, R. Guillonneau, M. Quareshy, A. Murphy, M.A. Mausz, R. Stirrup, B. Rihtman, M. aguiolo Ferretjans, J. Brandsma, J. Peterson, D.J. Scanlan et Y. Chen " A novel class of sulfur-containing aminolipids widespread in marine roseobacters " - 2021 - ISMEJ
• R. Guillonneau, C. Baraquet et M. Molmeret. " Marine bacteria display different escape mechanisms when facing their protozoan predators " - 2020 - Microorganisms
• R. Guillonneau, C. Baraquet, A. Bazire et M. Molmeret. " Multispecies biofilm development of marine bacteria implies complex relationships through competition and synergy and modification of matrix components " - 2018 - Frontiers in microbiology