The impact of metal on the composition and functionality of a microbial community

Description

The present research project focuses on two major points. We first examine the impact of a metal stress on (i) the composition and functionality of the microbial community and (ii) the spread of mobile genetic elements carrying (or not) a metal resistance operon and its expression in the community. Therefore, the in vitro system mimicks a real situation observed in the field. Representatives of the major taxa found in the first top millimetres of an industrial metal contaminated sediment (MetalEurop in Noyelles-Godault, North France) were selected. Five heterotrophic and aerobic strains were chosen for the synthetic community. They were obtained from culture collections and whose genome has been completely sequenced and annotated. Among them, Pseudomonas putida KT2440::Plpp mCherrry is used as donor carrying a pKJK5 broad host range plasmid that is pKJK5-gfpmut3-KmR -TcR or pKJK5-gfpmut3-Km-pbrTRABCD-TcR. These strains permit to detect and count donors and transconjugants by confocal microscopy or flow cytometry. The dynamic of the synthetic community will be followed by quantitative PCR, flow cytometry, MRM and metaproteomics to assess plasticity, conjugation rate and functionality of the community under metal stress in batch and biofilm culture.