Project description:Microbial communities that degrade lignocellulosic biomass are typified by high levels of species- and strain-level complexity, as well as synergistic interactions between both cellulolytic and non-cellulolytic microorganisms. Here we deconvoluted a highly efficient cellulose-degrading and methanogenic consortium (SEM1b) that is co-dominated by Clostridium (Ruminiclostridium) thermocellum and multiple heterogenic strains affiliated to C. proteolyticus. A time-series analysis was performed over the entire lifetime span of the microbial community and comprised of metagenomic, metatranscriptomic, metabolomics, metaproteomic and 16S rRNA gene analysis for 8 time points, in triplicate. Metagenomic analysis of SEM1b recovered metagenome-assembled genomes (MAGs) for each constituent population, whereas in parallel two novel strains of C. proteolyticus were isolated and sequenced. Both the recovered MAGs and the isolated strains were used as a database for further functional meta-omics. Absolute quantitative metatranscriptomics was performed thanks the spike-in of an in vitro transcribed RNA as an internal standard and label-free quantification was used for the metaproteomic analysis. The present dataset has been used for several publications. The first aim of the project was to characterize the interactions between uncultured populations in a lignocellulose-degrading community. Furthermore, because of the in-depth multi-omics characterization of the community, the dataset was used to develop new approaches for meta-omics integration as well as to assess the protein-to-RNA ratio of multiple microbial populations simultaneously. Modifications of multi-omics toolkits allowed us to assess the linearity between transcriptome and proteome for each population over time and reveal deeper functional-related trends and integrative co-dependent metabolisms that drive the overall phenotype of microbial communities.
Project description:Thiabendazole (TBZ), a benzimidazole used against postharvest fungal growth and as anthelmintic in livestock farming, is highly persistent in soil (DT50> 1-2 years) and therefore challenging concerning its environmental management. In our recent copious attempts to isolate organisms that degrade TBZ, at best, we ended up with a soil microbial enrichment capable of accelerated TBZ degradation. Here, we employed a multi-omic approach combined with DNA stable isotope probing (SIP) for elucidating the underlying system complexity. We obtained 18 high-quality metagenome-assembled genomes, with six being dominant and versatile concerning their putative xenobiotics degradation ability. SIP combined with microbiome analysis verified our previous results about the key role of a Sphingomonas strain in TBZ degradation. Next to this, metabolomics suggested minimal/no cross-feeding events, and Sphingomonas being the sole TBZ degrader. RNA sequencing and proteomics analysis of the consortium using TBZ or succinate as sole carbon sources showed the enhanced expression in Sphingomonas of a carbazole dioxygenase locus with putative role in the TBZ degradation. Gene expression networking analysis suggested the interaction of Sphingomonas with a Hydrogenophaga strain that possibly contributes to the overall cobalamin balance. Our study depicts the need for integrated omic approaches for understanding complex interactions frequently occurring in bioremediation.