Laboratory-scale simulation study on the bioremediation of marine oil pollution by phosphate-solubilizing bacteria Bacillus subtilis PSB-1

Phosphate-solubilizing bacteria (PSB) are well-known for their ability to convert nonbioavailable phosphates into bioavailable forms, however, research on PSB that possess both phosphate solubilization and crude oil degradation capabilities in marine environments has not yet been explored, and the role of these bacteria in microbial remediation of petroleum contamination in seawater needs be investigated. In this study, laboratory simulated marine oil spill bioremediation experiment was carried out to explore the role of PSB with crude oil degradation capabilities (A strain of PSB-1 used in this study) in petroleum hydrocarbon degradation by indigenous microorganisms in marine environment. It was found that PSB-1 significantly enhanced crude oil removal, with a degradation efficiency of 60% achieved after 30 days at a crude oil concentration of 1 g/L, Concurrently, the concentration of soluble phosphate in seawater increased to 47.36 mg/L, reflecting a 170% increase compared to the control. Metagenomic analysis further indicated that the phosphate-solubilizing activity of PSB-1 not only augmented phosphate availability but also stimulated the growth and succession of indigenous hydrocarbon-degrading microorganisms, thereby altering the microbial community structure and improving overall degradation capacity. These findings highlight the ecological significance of PSB-1 in facilitating crude oil biodegradation in marine environments and offer novel insights into bioremediation strategies for crude oil-contaminated seawater.