Niche differentiation and influencing factors of nitrite oxidation bacteria Nitrospira in sediments of the Luan River estuary in China

Abstract

In estuarine sediment, the nitrite oxidation process mediated by bacteria is significant in the nitrification process. Nitrospira is the most widely distributed in diverse group of nitrite-oxidizing bacteria (NOB), and can adapt to various environment. In this study, the Nitrospira-specific primer nxrB 169F-638R was used to analyze the microbial communities in the sediments of low-, middle-, and high-level zones of the Luan River estuary. The structure of microbial community and its response to environmental factors were discussed. The abundance and diversity of Nitrospira were the highest in the low-level zone and the lowest in the high-level zone. Lineage II (43.58%) and lineage IV (32.09%) were the dominant Nitrospira. It was found that the distribution pattern of Nitrospira was also affected by complex environmental factors such as the concentration of NH4+, Fe and Cu cations. Therefore, this study is helpful in understanding the niche differentiation and adaptation strategies of Nitrospira in an estuarine sediment environment and in providing references for single-step nitrification.