Christina HAZARD defends her HDR on Dec. 16th, 2024 at the École Centrale de Lyon, Amphi 3 building W1.
Title :
Soil microbial communities, interactions and contributions to biogeochemical cycling
Jury :
Rapporteurs :
Pr. Graeme Paton, University of Aberdeen
Pr. Christopher van der Gast, Northumbria University
Pr. Kalliope Papadopoulou, University of Thessaly
Examinateurs :
Pr. Agnès Richaume-Jolion, University Claude Bernard Lyon 1
Pr. Jean-Pierre Cloarec, École Centrale de Lyon
Abstract :
Our rapidly changing climate is the preeminent environmental challenge that humanity currently faces. The activity of microorganisms is central to controlling the fluxes of carbon (C) and nitrogen (N) through soils and other environments, including the production and removal of long-lived atmospheric greenhouse gases. The overarching theme of my research is to understand the fundamental underlying ecology of microbially-mediated contributions to biogeochemical cycling and developing approaches to either control or mitigate the deleterious environmental consequences of their activity. My initial research focus was examining the diversity and distribution of arbuscular mycorrhizal fungi (AMF) and their association with plants in various ecosystems. I developed this foundational research into understanding how AMF are involved in transferring inorganic N to plants. As nitrifying prokaryotes are responsible for the transformation and loss of soil N, including applied fertilizers, I have examined the competition between AMF and nitrifiers as a mechanism for increasing fertilizer use efficiency. Complementary to this, current and future research is focusing on other mechanisms for reducing the activities of nitrifying soil microorganisms responsible for fertilizer loss and transformation to polluting forms through manipulation of microbial communities using natural and synthetic chemical inhibitors. A recent novel research axis has been using prokaryotes involved in chemolithotrophic processes, such as nitrification, as a model system to exam host-virus interactions in the nascent field of soil virus ecology. Taking inspiration from the medical field where viruses are being used to treat infectious diseases to combat the rise of increasing antibiotic resistance, my group is also developing ‘phage therapy’ approaches as a natural yet highly-targeted approach for controlling microorganisms contributing to greenhouse gas production in soils and potentially other environments.
Publications :