一株苯并(a)芘高效降解菌的分离筛选及降解特性OA

[Objective]Utilizing microbial remediation technology for the efficient degradation of polycyclic aromatic hydrocar-bons(PAHs)is a research hotspot in environmental science.The isolation and screening of indigenous microbial strains with high degradation capacity were critical components of this technology.[Methods]To investigate the remediation effects of mi-croorganisms on the PAH benzo(a)pyrene(BaP)in industrially contaminated soils in Shanxi Province,over 20 organic-con-taminated soil samples were collected.A high-efficiency indigenous strain,Bacillus halotolerans B2,was screened and accli-mated.The following studies were carried out with strain B2:morphological observation,BaP tolerance,16S rDNA sequence analysis,and degradation characteristics.[Results]The isolate,identified as B.halotolerans,was Gram-positive and exhibited high BaP tolerance(>200 mg/L).A 14-day degradation test showed that the degradation rate peaked on the 12th day.Its maximum degradation rate of 55.54%was achieved under optimal conditions(10 mg/L BaP,pH 7,10%inoculum).Co-me-tabolism tests indicated that the addition of tryptone and starch provided the greatest enhancement,improving the removal rate by at least 25%.[Conclusion]These results highlighted the potential of strain B2 for the remediation of water or soil contami-nated with high-ring PAHs and provided a valuable theoretical basis for the future bioremediation of contaminated soil using high-efficiency degrading bacteria.