Diversity and distribution of bacterial community vertically across ecological and trophic gradient within sediments of lake Bosten area.

Sediment bacterial communities have potential to serve as a valuable bioindicator and integrator of water quality and local environment changes. However, bacterial community vertically across different ecotopes of Lake Bosten have been poorly understood. In this study, 16S rRNA high-throughput sequencing was used to assay the diversity of bacterial community, within sediments from three ecotopes Large Lake, Small Lake and Wetlands containing three depth intervals-surface (0-10) cm, middle (10-20) cm and deep (20-30) cm. The results indicated that the bacterial community exhibited apparent ecotope-dependent variations as well as orderly changes along the depth gradient. Although Proteobacteria, Actinobacteriota, Bacteroidota, Firmicutes and Chloroflexi were dominant phyla, their abundance varied across the ecotopes and depth intervals. Large Lake was complex in geography, and greatly displayed spatial heterogeneity, which further extended to Wetlands. Total organic carbon (TOC) and kjeldahl nitrogen (KN) were the main drivers of bacterial communities clustering across different ecotopes and depth intervals. PCoA and co-occurrence network results inferred, bacterial community in Large Lake is similar to that in Wetlands, whereas different from that in Small Lake. These results illustrated bacterial diversity varies within different ecotopes and depth intervals, the attention should be paid for the organic pollutions of Lake Bosten, and pathogenic factors in Small Lake.