Metagenomic analysis of the diversity of microbes in the Napahai plateau wetland and their carbon and nitrogen metabolisms

Due to the special geographical location and the complex ecosystem types, plateau wetlands play important ecological roles in water supply, greenhouse gas regulation and biodiversity preservation. Napahai plateau wetland is a special wetland type with low latitude and high altitude, and its microbial diversity was rarely studied. The diversity of microbial communities in the Napahai plateau wetland was analyzed using metagenomics method. Among the microbes detected, 184 phyla, 3 262 genera and 24 260 species belong to the bacterial domain, 13 phyla and 32 genera belong to the archaeal domain, and 13 phyla and 47 genera belong to the fungal domain. Significant differences in species diversity between soil and water were observed. Acidobacteria, Proteobacteria and Actinobacteria were dominant phyla in soil, while Proteobacteria and Bacteroides were dominant phyla in water. Since the carbon and nitrogen metabolism genes were abundant, the pathways of carbon fixation and nitrogen metabolism were analyzed. Calvin cycle, reductive tricarboxylic acid cycle and 3-hydroxypropionic acid cycle were the main carbon fixation pathways, while Proteobacteria, Chloroflexi, and Crenarchaeota were the main carbon-fixing bacteria group. As for the nitrogen cycle, nitrogen fixation and dissimilatory nitrate reduction were dominant in water, while nitrification and denitrification were dominant in soil. Proteobacteria, Nitrospirae, Verrucomicrobia, Actinobacteria, Thaumarchaeota and Euryarchaeota contributed to the nitrogen cycle. The study on microbial diversity of Napahai plateau wetlands provides new knowledge for the comprehensive management and protection of wetland environment in China.