Effective degradation of polychlorinated biphenyls by a facultative anaerobic bacterial consortium using alternating anaerobic aerobic treatments.
Effective degradation of polychlorinated biphenyls by a facultative anaerobic bacterial consortium using alternating anaerobic aerobic treatments.
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DOI：
10.1016/j.scitotenv.2018.12.385
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发表时间：
2019-04
期刊：
影响因子：
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通讯作者：
G. Pathiraja;P. Egodawatta;A. Goonetilleke;V. Te’o
中科院分区：
文献类型：
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作者：
G. Pathiraja;P. Egodawatta;A. Goonetilleke;V. Te’o
多氯联苯 (PCB) 是氯化烃化合物的合成混合物，过去被广泛使用，由于其高度顽固性，至今仍存在于环境中。厌氧脱氯和有氧氧化的结合对于将这些 PCB 混合物降解为毒性较低的产品至关重要。据推测，由于 PCB 混合物的复杂性，精心挑选的合适微生物物种的联合体将比单个微生物的应用表现更好。在本研究中，研究了商业 PCB 混合物 Aroclor 1260 在两种不同的厌氧-需氧组合条件下的生物降解，即交替 (AN) 和两阶段 (TS)。兼性厌氧细菌群由天然存在的无色杆菌组成。 NP03，苍白杆菌。 NP04 和赖氨酸芽孢杆菌属 sp. NP05。这些细菌被发现能够在厌氧和有氧条件下溶解和降解多氯联苯。 AN 治疗两周后，原始 50mg/L Aroclor 1260 混合物总体减少了 49.2±2.5%，而 TS 治疗仅减少了 24.44±2.46%。在第 6 周结束时，AN 条件下测得的氯化物释放量为 17.63±0.91mg/L，而 TS 条件下测得的氯化物释放量为 11.79±1.28mg/L。总体结果表明，能够在厌氧和好氧条件下降解和利用 PCB 的微生物群落通过交替暴露于短时间的厌氧和好氧条件而不是传统的两阶段厌氧-好氧条件，实现了更好的 PCB 降解。
Polychlorinated biphenyls (PCBs) are synthetic mixtures of chlorinated hydrocarbon compounds that were widely used in the past and still found in the environment due to their highly recalcitrant nature. A combination of anaerobic dechlorination and aerobic oxidation is essential to degrade these PCB mixtures into less toxic products. It was hypothesized that due to the complexity of PCB mixtures, a consortium of carefully selected suitable microbial species will perform better than the application of individual microbes. In the present study, biodegradation of the commercial PCB mixture, Aroclor 1260, was studied under two different combined anaerobic-aerobic conditions, namely, alternating (AN) and two stage (TS). The facultative anaerobic bacterial consortium consisted of naturally occurringAchromobactersp. NP03,Ochrobactrumsp. NP04 andLysinibacillussp. NP05.These bacteria were found capable as individuals of solubilizing and degrading PCBs under both anaerobic and aerobic conditions. 49.2 ± 2.5% total reduction of the original 50 mg/L Aroclor 1260 mixture was achieved after 2 weeks in AN treatment whereas the reduction was only 24.44 ± 2.46% in TS treatment. At the end of week 6, a yield of 17.63 ± 0.91 mg/L chloride released was measured under AN condition compared to 11.79 ± 1.28 mg/L measured under TS condition. The overall results suggested that the microbial consortia capable of degrading and utilizing PCBs under both, anaerobic and aerobic conditions achieved better PCB degradation by repeated exposure to short periods of anaerobic and aerobic conditions alternatingly rather than the conventional two stage anaerobic-aerobic conditions.