Carbon–Nitrogen–Sulfur-Related Microbial Taxa and Genes Maintained the Stability of Microbial Communities in Coals

Abstract

Coal microbes are the predominant form of life in the subsurface ecosystem, which play a vital role in biogeochemical cycles. However, the systematic information about carbon–nitrogen–sulfur (C–N–S)-related microbial communities in coal seams is limited. In this study, 16S rRNA gene data from a total of 93 microbial communities in coals were collected for meta-analysis. The results showed that 718 functional genera were related to the C–N–S cycle, wherein N 2 fixation, denitrification, and C degradation groups dominated in relative abundance, Chao1 richness, Shannon diversity, and niche width. Genus Pseudomonas having the most C–N–S-related functions showed the highest relative abundance, and genus Herbaspirillum with a higher abundance participated in C degradation, CH 4 oxidation, N 2 fixation, ammoxidation, and denitrification. Such Herbaspirillum was a core genus in the co-occurrence network of microbial prokaryotes and showed higher levels in weight degree, betweenness centrality, and eigenvector centrality. In addition, most of the methanogens could fix N 2 and dominated in the N 2 fixation groups. Among them, genera Methanoculleus and Methanosaeta showed higher levels in the betweenness centrality index. In addition, the genus Clostridium was linked to the methanogenesis co-occurrence network module. In parallel, the S reduction gene was present in the highest total relative abundance of genes, followed by the C degradation and the denitrification genes, and S genes (especially cys genes) were the main genes linked to the co-occurrence network of the C–N–S-related genes. In summary, this study strengthened our knowledge regarding the C–N–S-related coal microbial communities, which is of great significance in understanding the microbial ecology and geochemical cycle of coals.

Insights into the ecological roles of assembling genomes for stimulated methanogenic archaea Methanoculleus in coal seams

“…In this study, cys gene was the main sulphate reduction gene in MAG. Li et al (2022) showed that sulphur reduction genes are mainly dominated by the cys genes, and also showed the core linking of the network co-occurrence of the C-N-S genes in coal seams. Besides, sulphates and other substances participate in reactions that convert organic substances into acetate (Matsuura et al, 2021).…”

Metagenomics reveals biogeochemical processes carried out by sediment microbial communities in a shallow eutrophic freshwater lake

“…Except for C metabolism, the biogeochemical processes of N and S also affected the biodegradation in sediments. Microbial groups related to N metabolism, including N 2 fixation groups and denitrification groups, could improve N availability, because bioavailable N was a major limiting factor in nutrient poor environments ( Li et al, 2022 ). In our study, we found that the relative abundance of each module of the C-N-S cycle was consistent in each sample site, but its absolute abundance was different.…”