Project description:<p>A variety of anthropogenic organohalide contaminants generated from industry are released into the environment, and thus cause serious pollution that endangers human health. In the present study, we investigated the microbial community composition of industrial saponification wastewater using 16S rRNA sequencing, providing genomic insights of potential organohalide dehalogenation bacteria (OHDBs) by whole-metagenome sequencing. We also explored yet-to-culture OHDBs involved in the microbial community. Microbial diversity analysis reveals that Proteobacteria and Patescibacteria phyla dominate microbiome abundance of the wastewater. In addition, a total of six bacterial groups (Rhizobiales, Rhodobacteraceae, Rhodospirillales, Flavobạcteriales, Micrococcales, and Saccharimonadales) were found as biomarkers in the key organohalide removal module. Ninety-four metagenome-assembled genomes (MAGs) were reconstructed from the microbial community, and 105 hydrolytic dehalogenase genes within 42 MAGs were identified, suggesting that the potential for hydrolytic organohalide dehalogenation is present in the microbial community. Subsequently, we characterized the organohalide dehalogenation of an isolated OHDB, Microbacterium sp. J1-1, which shows the dehalogenation activities of chloropropanol, dichloropropanol, and epichlorohydrin. This study provides a community-integrated multi-omics approach to gain functional OHDBs for industrial organohalide dehalogenation.</p>
Project description:Lignin is the most abundant renewable source of aromatic carbon and its microbial depolymerization and metabolism under aerobic conditions is well studied. However, lignin breakdown in the absence of oxygen remains poorly understood. Here, we established long-term bacterial enrichment cultures supplied with diverse lignins as the sole carbon source under denitrifying conditions. Denitrification dynamics were followed by monitoring nitrogenous gases. Metagenomics analysis recovered 62 metagenome-assembled genomes (MAGs), several of which encoded enzymes for both denitrification and anaerobic metabolism of aromatic compounds. Quantitative metaproteomics confirmed expression of such enzymes and additionally showed that several MAGs expressed redox-active auxiliary-activity enzymes and other uncharacterised proteins that are potential candidates for involvement in lignin depolymerisation. The detection of several oxygen-dependent oxidoreductases despite anaerobic conditions prompt intriguing discussion of potential mechanistic explanations. This systems-level study expands our understanding of lignin turnover in anaerobic environments by bacteria and suggest enzymatic targets for further exploration of their role in lignin depolymerization under oxygen-limited conditions.
Project description:This study investigates temporal dynamics in microbial community function within the freshwater ecosystem of Lake Zurich, Switzerland, over three months (36 timepoints). Metagenome-assembled genomes (MAGs) and metaproteomes were analyzed to identify species-specific and community-level protein expression patterns. The study explores how bacterial species contribute to ecosystem functioning through protein-level activity, focusing on relationships between species taxonomy, abundance, and protein investment patterns.
Project description:Marine sponges are essential for coral reefs to thrive and harbour a diverse microbiome that is thought to contribute to host health. Although the overall function of sponge symbionts has been increasingly described, in-depth characterisation of each taxa remains challenging, with many sponge species hosting up to 3,000 distinct microbial species. Recently, the sponge Ianthella basta has emerged as a model organism for symbiosis research, hosting only three dominant symbionts: a Thaumarchaeotum, a Gammaproteobacterium, and an Alphaproteobacterium and a range of other minor taxa. Here, we retrieved metagenome assembled genomes (MAGs) for >90% of I. basta’s microbial community which allowed us to make a complete metabolic reconstruction of the sponge’s microbiome, identifying metabolic complementarity between microbes, as well as the importance of symbionts present in low abundance. We also mined the metagenomes for putative viral sequences, highlighting the contribution of viruses to the overall metabolism of the sponge, and complement this data with metaproteomic sequencing to identify active metabolic pathways in both prokaryotes and viruses. This data now allows us to use I. basta as a model organism for studying host-microbe interactions and provides a basis for future (genomic) manipulative experiments.