Haodong Yi, Feifei Chai, Xingping Hang, Jue Dai, Xiaoxiao Feng, Fangjun Zhao, Lu Jiang, Shuai Chen
The microbial succession in activated sludge for the treatment of oily wastewater from ships was investigated by high-throughput sequencing of the 16s rRNA gene, and the microbial metabolic pathways of sulphur were determined. Proteobacteria was the dominant phylum, with a relative abundance of 57.2%-88.0%, and Thiobios and Thiobacillus played an important role in the associated sulphur metabolism. Diversity and species differentiation analyses showed that sample A4 after 1 year of domestication had the lowest species diversity. The species with large differences were Thiobios, SM1A02, Thiobacillus, and Flavobacterium. Sulphite oxidation to sulphate occurs through the sulphite oxidase (SO) pathway. Sulphur-oxidising bacteria such as Thiobios and Thiobacillus convert sulphite into sulphate through the SO pathway using sulphite-oxidising enzymes. In addition, the sulphite dehydrogenase and reverse heterogeneous sulphate reduction pathways were predicted. These pathways may jointly participate in and regulate the sulphur cycle during the treatment process of oily wastewater from ships. This paper systematically reveals the succession patterns of functional microorganisms in the biological treatment of oily wastewater from ships and the key sulphur metabolic pathways, providing a microbiological basis for optimising the biological treatment process of oily wastewater from ships and enhancing the efficiency of sulphur metabolism.