Variation of soil microbial communities on the shores of lake Daihai and their potential use as biomarkers

• The diversity and composition of soil microorganisms are influenced by pH, salinity, AK, AP, and S. • Lakeshore soil microbial community assembly processes are dominated by determinism and stochasticity. • Biomarkers play an important role in metabolic functions. Despite significant progress in current research on the microbial structure in the soils on the shores of saline and freshwater lakes, the factors that drive the compositional structure of soil microbial communities on the shores of brackish lakes, as well as the processes of microbial community assembly, remain unknown. This study examined the spatial distribution of soil microbial communities on the shores of Lake Daihai, China, as well as their diversity and composition. In addition, it explored the environmental factors affecting these communities and their potential microbial functions. Illumina MiSeq high-throughput sequencing technology was the main tool of this study, the microbial community composition on the lakeside in different directions and along different distance gradients. Specifically, the focus was on differences in abundance and structural diversity. The diversity analysis and phylogenetic analysis showed that the microbial communities distributed in different directions were different and those along different distance gradients were not significantly different, but some microbial communities still have preferences. Microbial community assembly in the DLN is dominated by deterministic processes, and the other directions are dominated by stochastic processes. Linear discriminant analysis effect size and molecular ecological network analysis revealed that the network complexity of DLW was lower than that of the other three directions, and the presence of some unique taxa in the lakeshore soil, indicating that environmental factors have a key role in shaping microbial communities, and these taxa could therefore serve as potential soil biomarkers. At the same time, it was found that biomarker diversity varied significantly among species inhabiting different habitats, and different types of microorganisms were shown to function as a cohesive collective in the soil. Multiple regression analysis and partial Mantel test indicated that the soil microbial diversity and composition were driven by environmental factors such as pH, salinity, available potassium, available phosphorus and sulfur (AK, AP, and S), and that microbial flora played an important role in soil nutrient cycling. In summary, this study revealed the distribution pattern and assembly process of microbial communities in the lakeside soil of Lake Daihai and the environmental factors affecting them. The results obtained deepen our insights into the microbial communities in arid lakeside wetland ecosystems and are significant for their stewardship and conservation.