苯并(a)芘降解菌的筛选及其降解特性研究

    Screening and Characterization of Benzo (a) pyrene Degrading Bacteria and Their Degradation Properties

    • 摘要: 高分子量多环芳烃(PAHs)特别是苯并(a)芘(BaP)高效降解微生物资源仍十分匮乏。该研究通过富集培养、形貌观察、生理生化和16S rDNA基因序列对比分析等方法, 筛选获得4株BaP高效降解菌H1(Brucella anthropi, 布鲁氏菌)、H2(Bacillus cereus, 芽孢杆菌)、M1(Brucella anthropi, 布鲁氏菌)和M2(Brucella anthropi, 布鲁氏菌), 在不同温度、pH值条件下探究4株菌对BaP的降解特性后发现: (1)4株菌可在pH值为5.5~8.5, 温度(T)为25~37 ℃的环境中生存并保持活性, 最佳环境条件均为温度T=30 ℃, pH=7.5;(2)在T=30 ℃, pH=7.0条件下, 降解初始质量浓度为5 mg·L-1的BaP 5 d后, H1、H2、M1和M2对BaP的降解率分别达到66.32%、79.26%、82.14%和61.81%;(3)布鲁氏菌M1在最佳降解条件下对高分子量PAHs BaP具有良好的降解能力, 在微生物修复中具有较好的应用潜力。研究结果可为生物修复提供宝贵的生物资源, 为BaP污染环境的高效微生物修复提供技术支持。

       

      Abstract: Efficient microbial resource for degrading high-molecular-weight polycyclic aromatic hydrocarbons (PAHs), especially benzo(a)pyrene (BaP), is still lacking. This study screened and obtained four BaP-efficient degrading bacteria, H1 (Brucella anthropi), H2 (Bacillus cereus), M1 (Brucella anthropi) and M2 (Brucella anthropi), through enrichment culture, morphology observation, physiological and biochemical analysis and 16S rDNA gene sequence comparison. The degradation characteristics of the four strains under different temperatures and pH values were investigated. The results show that: (1) All the four strains could survive and maintain activity in an environment with pH of 5.5-8.5 and temperature of 25-37 ℃, and the optimal conditions for all were temperature of 30 ℃ and pH of 7.5; (2) Under the condition of T=30 ℃ and pH=7.0, after 5 days of degradation of BaP with an initial mass concentration of 5 mg·L-1, the degradation rates of H1, H2, M1, and M2 reached 66.32%, 79.26%, 82.14% and 61.81%, respectively; (3) Brucella anthropi M1 showed especially excellent degradation ability for high-molecular-weight PAH BaP under the optimal degradation conditions and had good application potential in bioremediation. The research results provide valuable biological resources for bioremediation and technical support for the efficient bioremediation of BaP-polluted environments.

       

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