The structure and diversity of denitrifying bacteria mediated by suspended particulate matter in aquaculture water bodies in Higher place pond

Abstract Suspended particulate matter (SPM) was an important part of aquaculture water and provides an important carrier for denitrification. SPM with different particle sizes were collected in the high place pond in Dianbai District of Maoming City. Phylogenetic diversity, community composition and their relationships with environmental factors were studied by high-throughput sequencing、fluorescence quantitative PCR and statistical analysis. The results showed that Proteobacteria was the dominant phylum of microbial community structure in aquaculture environment. The community of denitrifying bacteria mediated by SPM with different particle sizes was different. Low concentration and nutrient concentration made nitrifying archaea distributed in small particle size SPM. Moreover, the abundance of denitrification functional genes showed a trend of 5μm > 1μm > 0.22μm on SPM in the same site. The pH, DO, COD and TSS were the key factors affecting the niche distribution of denitrifying bacteria on SPM in the high place pond. These findings were crucial for deepening our understanding of the microbiology of nitrogen cycle processes such as denitrification and optimizing wastewater treatment strategies.