水稻土泥浆体系中多氯联苯的微生物厌氧脱氯

考察了厌氧水稻土泥浆体系中高氯代多氯联苯混合物Aroclor1260的脱氯过程，并对体系中的微生物群落结构变化进行分析.结果表明： Aroclor1260可在厌氧水稻土泥浆体系中发生脱氯，经过128 d，总消减率达到55.5%，在泥浆体系中引入驯化的脱氯富集培养体反而使脱氯效果下降，消减率为46.9%.Aroclor1260的主要脱氯过程发生在五、六、七氯联苯，其中七氯联苯脱氯过程最显著，五氯联苯作为脱氯产物有一定累积.有机物厌氧发酵产生的H₂会被脱氯过程所消耗，从而将体系中的氢分压维持在较低水平，抑制产甲烷过程而保证脱氯过程的持续进行.不同条件和培养方式驯化得到的微生物群落结构差异较大,富集培养体引入可能导致其与原体系中脱氯相关菌群竞争，从而改变体系原有菌群结构，这可能是导致其脱氯效率下降的原因.

Microbial anaerobic dechlorination of polychlorinated biphenyls in paddy soil slurry.

We studied the dechlorination process of Aroclor1260, a high chlorinated polychlorinated biphenyls (PCBs) mixture in an anaerobic paddy soil slurry, and further analyzed the related mic robial community structures. The Aroclor1260 was reduced up to 55.5% in the natural paddy soil slurry in 128 days, and the reduction percentage dropped to 46.9% after incoculating the paddy soil slurry with a PCBs dechlorination enrichment culture. The dechlorination mainly occurred in congeners of pentachlorobiphenyl, hexachlorobiphenyl, and specially, the heptachlorobiphenyl, with pentachlorobiphenyl accumulated as dechlorination intermediate. Hydrogen gas produced from fermentation of organic matters was maintained at a lower partial pressure due to its consumption during the dechlorination process, so that the methanogens was suppressed as well. The microbial community structure was significantly different between natural and inoculated paddy soils. Introducing the PCBs dechlorination enrichment culture changed the local microbial community by the competition between the exogenetic dchlorinators and the indigenous bacteria, overall decreasing the dechlorination activity.