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Seminar | Computing, Environment and Life Sciences

Physical and Chemical Controls on Habitats for Microbial Life: Examples of Aquifer Groundwater and Dust Microbial Communities

CELS Seminar

Abstract: In both natural and human-impacted environments, chemical conditions affect microbial community structures and functions. My research focuses on elucidating links between specific conditions and the structures and functions that they affect.

During my Ph.D. at the Université de Rennes 1, my research focused on the impacts of hydrological circulation and groundwater residence time on local geochemistry and residing groundwater microbial communities in three distant aquifers in Brittany (France). This study showed a geochemical compartmentalization of each aquifer reflecting the stark differences in groundwater residence time. The groundwater residence time was found to be strongly correlated with the type of microbial community structures observed, suggesting a strong influence of hydrological flowpaths on groundwater microbial communities. As Brittany is a region of intense agricultural activity, groundwater chemical conditions and microbial community structures in shallow groundwater were also largely impacted by these anthropogenic activities (e.g., pollution in nitrate). In this context, ecological function is tightly linked to community structure. However, that is not always the case, particularly when the function of interest is contained within mobile genetic elements.

In my postdoctoral work in Northwestern University, I developed a new analytical strategy to predict the dissemination potential of antibiotic resistance genes based on metagenomic data and antimicrobial concentrations in dust. Using traditional microbiology techniques, I confirmed the predicted ability of antibiotic resistance genes to disseminate. Together, these studies have clarified our understanding of how specific chemical features of microbial habitats impact the structures and functions of the communities found therein.

Bio: Sarah Ben Maamar obtained her bachelor’s degree in biochemistry and molecular biology at the Universite de Rouen (France) in 2009.She received a master’s degree in fundamental and applied microbiology from the University de Bretagne Occidentale (France) and Ph.D. in earth sciences at the Universite de Rennes 1. Sarah’s main interests are in coupling metagenomics and chemistry, microbial cultivation, and bioinformatics.