Summer and winter phylogenetic diversity of Archaea in light-color type soil crusts from Desert Hunsandake

Abstract:

[Objective] Biological soil crusts (BSCs) play an important role in restoring the ecological environment and constraining soil desertification. Microorganisms are important in the development of BSCs. However, the investigation on the microbial composition of BSCs is still limited now, especially is rare about archaea. [Methods] We constructed and analyzed archaeal 16S rRNA gene library to discover the diversity and phylotype composition of BSCs archaea from Desert Hunsandake, compared the variation between summer and winter. [Results] BSC samples were thin and brown with low levels of nitrogen and phosphate nutrients. The coverages of both libraries of August and November were over 95% and strongly representative. In total 142 archaeal 16S rRNA sequences were obtained from the two libraries and these sequences were divided into 10 operational taxonomic units (OTUs) with the cutoff value of 0.03. In both libraries the predominant OTU was the same, probably a unique group in desert. All sequences obtained from this study were originated from members of Thaumarchaeota, the third phylum of Archaea, but a large difference in community structure was observed between the two libraries of August and November. Only one unique OTU was found in August and four in November. Archaeal diversity in BSCs is low and yet the diversity of November was higher than that of August. [Conclusion] Archaea in light-colored BSCs from temperate desert is dominated by the Thaumarchaeota species with lower diversity and the community structure largely varies with season changing.

Key words:16S rRNA, Operational taxonomic unit (OTU), Thaumarchaeota, Community structure