Research on aerobic oxidation of methane bacteria and its influencing factors in Chongqing central city section of the Yangtze River, China

Bacterial communities play an important role in the carbon cycle of freshwater ecosystems. In order to understand the influencing factors of bacterial community in the process of carbon cycle and search for measures to reduce carbon emissions, Chongqing central city section of the Yangtze River and its tributaries were selected to be the study area in this research. High-throughput sequencing was applied to study aerobic oxidation of methane bacteria (MOB) in sampling area. The results showed that there were spatial differences in the community diversity of aerobic MOB in the Yangtze River in central Chongqing. The Shannon index in the sediment (2.389–2.728) was higher than that in the water (1.820–2.458), and the community diversity in the middle reaches of the main river was higher than that in the upstream and the downstream. The aerobic MOB community was mainly dominated by Type II ( Methylocystis ). Most of operational taxonomic units (OTUs) in the top ten had high homology with MOB from river and lake sediments, and a few OTUs had high homology with MOB from paddy fields, forests and wetland soils. The main environmental factors affecting the community structure of aerobic MOB were NH 4 + -N, dissolved oxygen (DO), temperature (T, p ≤ 0.001), pH ( p ≤ 0.05), methane (CH 4 ) and carbon dioxide (CO 2 ).