Diversity of Bacterium Communities in Saline-Alkali Soil in Arid Regions of Northwest China

Background: The Illumina MiSeq sequencing method was practiced to investigate the bacterial diversity and composition in the 5 subtypes and 13 genera of saline-alkali soil in Gansu Province, China. Results: : The results from this study show that the dominant bacterial groups were Euryarchaeota , Proteobacteria , Bacteroidetes , Actinobacteria , Firmicutes , and Gemmatimonadetes among the different salinity soil. Euryarchaeota and Proteobacteria were the main indicator species reflecting changes of the main microbial groups. Euryarchaeota was the most abundant in chloride-sulfate-type meadow solonchaks, sulfate-chloride-type meadow solonchaks, chloride-type meadow solonchaks, chloride-sulfate-type orthic solonchaks, sulfate-chloride-type orthic solonchaks, magnesium solonetz, sulfate-type dry solonchaks, chloride-sulfate-type dry solonchaks, and sulfate-chloride-type dry solonchaks, whereas Proteobacteria had the greatest abundance in sulfate-type meadow solonchaks, sulfate-type orthic solonchaks, chloride-type orthic solonchaks, and chloride-type bog solonchaks. Halobacteria was the dominant bacterial class in soil samples except sulfate-type meadow solonchaks, chloride-type orthic solonchaks, sulfate-type orthic solonchaks, and chloride-type bog solonchaks. The richness estimators of Ace and Chao 1 and the diversity indices of Shannon and Simpson revealed a less bacterial community in sulfate-chloride-type orthic solonchaks than that of other soils. Conclusions: : The pH value was the most important driving force for bacterial composition (32.1%), and the second most influencing factor was sulfate anion (9.2%) and soil total salt (8.7) contents.