Reciprocal impacts between microbial community and trace metal contamination in a highly contaminated area: the Toulon Bay (France)

Beginning: October 2015
Defence: June 26th 2019

Abstract:

During my PhD, I’m using microbial genomics and metagenomics as well as environmental biogeochemistry skills, particularly in the marine environment. I explore marine microbial community interactions with trace metal contamination in a marine coastal area facing important anthropogenic pressures. I conduct high frequency on-field surveys and I carry this research into laboratory, where I work in controlled conditions to explored specific influence of trace metals. Then, I study spatio-temporal dynamics of marine bacterioplankton and microbial biofilm communities in relation to a large spectrum of physico-chemical (oceanographic properties and nutrients), geochemical (22 metal elements) and biological (phytoplankton abundance) parameters. By using 16S rRNA gene MiSeq sequencing, flow cytometry and both electrochemistry and HR-ICP/MS as well as bioinformatic tools, we demonstrate that trace metal contamination appears to be a very significant driver of microbial communities in urbanized coastal areas when compared to other environmental parameters. Such contamination appears to impair microbial abundance, diversity as well as community structure and microbial functioning through a combination of both direct and indirect effects linked to biotic interactions.