Assessment of the Effect of Soil Physico-Chemical Properties on the Bacterial Community Structure
The physico-chemical properties of soils determine their potential as a habitat for living species. They influence the state of soil flora and fauna, the diversity of soil microbiome in particular. In the present study, particle size distribution, pH, and organic carbon content have been analyzed in 25 soil samples representing 8 different soil types. It has been found that the pH values vary in the range from 5.05 (sample no. 4) to 7.29 (sample no. 19), while the organic carbon content change from 0.72% (sample no. 2) to 4.54% (sample no. 19). According to the analysis of particle size distribution, particles of 2-50 μm in size dominate in the majority of samples and particles greater 50 μm occur in samples no. 5 and 6. The species composition and abundance of bacteria in the soil samples have been estimated by the Illumina MiSeq method. A total of 443 unique OTUs have been identified in 6 soil samples. The dominant taxa at the phylum level include Verrucomicrobia, Proteobacteria, Gemmatimonadetes, Bacteroidetes, Actinobacteria, Acidobacteria, while Chloroflexi phylym is also abundant in samples no. 18, 12, 19, and 23. The MDS (multidimentional scaling) method has been used to determine the similarities and differences between the soil samples based on: 1) their physico-chemical characteristics and 2) bacterial diversity. It has been shown that the physico-chemical characteristics are not the only determinants for the structure of soil bacterial community.