Bacillus subtilis Strain YJ-15, Isolated from the Rhizosphere of Wheat Grown under Saline Conditions, Increases Soil Fertility and Modifies Microbial Community Structure

Soil salinization during wheat cultivation considerably diminishes soil fertility and impedes wheat growth, primarily due to rhizosphere microbial community changes. Our study investigates the application of <i>Bacillus subtilis</i> YJ-15, a strain isolated from the rhizosphere of wheat cultivated in salinized soil, as a soil remediation agent. This strain has demonstrated significant salt tolerance, disease suppression capabilities, and growth-promoting attributes in previous studies. The wheat rhizosphere was examined to assess the impact of <i>Bacillus subtilis</i> YJ-15 on microbial community composition and soil fertility. Fertility of soil in saline soil was significantly increased by inoculating wheat with YJ-15. The microbial community structure within the wheat rhizosphere inoculated with <i>Bacillus subtilis</i> YJ-15 was analyzed through sequencing on the Illumina MiSeq platform. Phyla Proteobacteria and Acidobacteria were identified as the dominant bacteria. Basidiomycota, Mortierellomycota, and Ascomycota dominated the fungal phyla. Among the bacterial genera, <i>Pseudomonas</i>, <i>Arthrobacter</i>, and <i>Bacillus</i> were predominant. The predominant fungal genera included <i>Alternaria</i>, <i>Cephalotrichum</i>, <i>Mortierella</i>, and <i>Chaetomium</i>. A significant increase in <i>Gaiella</i> and <i>Haliangium</i> levels was observed in the YJ group compared to the control group. Additionally, the fungal genera <i>Epicoccum</i>, <i>Sporidiobolus</i>, and Lecythophora have significantly increased in YJ abundance. One of the potential benefits of <i>Bacillus subtilis</i> YJ-15 in the cultivation of wheat on salinized land is its ability to enhance the rhizosphere microbial community structure and improve soil fertility.