Several decades of intensive farming and climate change have profoundly degraded soil quality, leading to an erosion of its biodiversity. In the long term, this could have serious consequences for food production, making it urgent to understand soil ecosystems and their balances in order to develop new sustainable practices. This is a major challenge, since soil biodiversity involves complex interactions among microorganisms, fungi, plants, and small animals.
In this seminar, I will present our ongoing research aimed at understanding the role played by bacterial predators in soil ecosystems. Starting from molecular mechanisms of predation dissected in the laboratory, I will describe the approaches we are developing to unravel real ecological interactions. Finally, I will present our objectives regarding the potential applications of these studies for the agriculture of tomorrow.

Tâm Mignot is a microbiologist by training. After his graduate studies at the University of Nice Sophia Antipolis, he completed a thesis at the Institut Pasteur in Michèle Mock’s lab where he studied the regulation of surface protein synthesis in the anthrax bacillus, Bacillus anthracis. After his Ph.D. in June 2002, he joined David Zusman’s team at the University of California, Berkeley, where he worked on the mechanisms of bacterial motility in the model bacterium Myxococcus xanthus. He was recruited in 2006 as a research fellow at CNRS. Since 2007, Tâm Mignot has been studying the mechanism by which bacteria move on surfaces and direct their movement to adopt social behaviors, like schools of fish that are able to reorganize very quickly according to environmental conditions. In general, this research aims to define the cellular interactions allowing multicellular coordination on large scales. Over the past decade, the team has used “single cell” approaches to study the molecular mechanisms of motility and its regulation. Recently, the team has developed new tools to integrate these mechanisms at the ecological scale and model the emergence of social behaviors such as bacterial predation. Tâm Mignot is an elected member of the European Academy of Microbiology, a member of the French Academy of Scienes, and the recipient of several awards, including ERC starting (2010) and Advanced grants (2020), the “Coup d’élan” Prize for French research from the Bettencourt Schueller Foundation, the CNRS Bronze (2011) and Silver (2023) Medals.