Abstract:

Metagenomics sequencing was used to reveal the diversity of genes and their metabolic pathways involved in carbon sequestration and nitrogen fixation in moss crusts in Shapotou region, located southeast of the Tengger Desert. Results showed that the microbial community related to the bacteria domain in the moss crust was the largest, followed by archaea and eukaryota. In the bacterial domain, the most abundant phyla was the Actinobacteria, followed by the Proteobacteria and Cyanobacteria. Based on the functional classification of eggNOG and KEGG databases for the functional prediction of non-redundant gene catalog, the diversity of gene and metabolic pathways in the moss crust soil was high. Low nitrogen fixation was found in the moss crust as there are less metabolic pathways related to nitrogen-fixation, weakening the ecological function of ammonia synthesis from atmosphere nitrogen. The nitrate from the nitrogen pool formed by moss crust were mainly reduced to ammonium salt by nitrate reduction pathway, which may be used for the synthesis of amino acids for microbiome in the moss crust, and may also provide an effective nitrogen source for the growth of mosses.

Key words: microbial communities, biological soil crust, Shapotou Desert, HiSeq sequencing