Soil Geochemical Properties Influencing the Diversity of Bacteria and Archaea in Soils of the Kitezh Lake Area, Antarctica

SIMPLE SUMMARY: Global warming has always been a topic of concern for people. The polar regions are an ideal research area to study the impact of global warming because they are less affected by human activities. Seasonal meltwater lakes are a typical landscape in which parts of the soil are covered with water in the summer and exposed to air in the winter. In this study, three types of soils, including BPK (always above water), INT (sometimes above water, sometimes underwater), and SED (always underwater), were selected from the Kitezh Lake area in Antarctica to investigate the relationship between soil geochemical properties and bacterial and archaeal diversity and community structure. The key geochemical factors were found through RDA (CCA), and the network diagrams were drawn by WGCNA to find the hub OTUs. The results showed that pH, phosphate, nitrite, moisture content, ammonium, nitrate, and total carbon content all played important roles in bacterial and archaeal diversity and structure at different sites. This work provides an idea for future microbial diversity analysis, which is finding hub OTUs through WGCNA. Under the aggravation of global warming, this study also makes a contribution to predicting changes in soil microbial communities in lake regions. ABSTRACT: It is believed that polar regions are influenced by global warming more significantly, and because polar regions are less affected by human activities, they have certain reference values for future predictions. This study aimed to investigate the effects of climate warming on soil microbial communities in lake areas, taking Kitezh Lake, Antarctica as the research area. Below-peak soil, intertidal soil, and sediment were taken at the sampling sites, and we hypothesized that the diversity and composition of the bacterial and archaeal communities were different among the three sampling sites. Through 16S rDNA sequencing and analysis, bacteria and archaea with high abundance were obtained. Based on canonical correspondence analysis and redundancy analysis, pH and phosphate had a great influence on the bacterial community whereas pH and nitrite had a great influence on the archaeal community. Weighted gene coexpression network analysis was used to find the hub bacteria and archaea related to geochemical factors. The results showed that in addition to pH, phosphate, and nitrite, moisture content, ammonium, nitrate, and total carbon content also play important roles in microbial diversity and structure at different sites by changing the abundance of some key microbiota.