Bacterial and archaeal communities in saline soils from a Los Negritos geothermal area in Mexico

In recent years, there has been a growing need to understand how salinity affects microbial communities in agricultural soils. Archaeal and bacterial community diversities and structures were investigated by high-throughput sequencing analysis of their 16S rRNA in two arable soils with low electrical conductivity (EC) (2.3 and 2.6 dS m^–1) and a saline soil (EC = 17.6 dS m^–1). The dominant bacterial phyla in the soils were Proteobacteria (relative abundance (RA) = 46.2%), followed by Acidobacteria (RA =13.1%) and Actinobacteria (RA = 10.0%), whereas Serratia (RA = 6.0%) and Bacillus (RA = 4.0%) were the dominant bacterial genera. Candidatus Nitrososphaera (53.5%) was the dominant archaeal phylotype in the arable soils, whereas Nitrosopumilus (RA = 0.4%) dominated in the saline soil. The archaeal and bacterial community structures were different between the soils and significantly correlated with soil sand, arsenic, barium, and antimony contents, but not with soil salinity.