Development and characterization of stable sediment-free anaerobic bacterial enrichment cultures that dechlorinate Aroclor 1260
Development and characterization of stable sediment-free anaerobic bacterial enrichment cultures that dechlorinate Aroclor 1260
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DOI：
10.1128/aem.72.4.2460-2470.2006
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发表时间：
2006-04-01
影响因子：
4.4
通讯作者：
Jerzak, GV
中科院分区：
文献类型：
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作者：
Bedard, DL;Bailey, JJ;Jerzak, GV
我们已经开发了无沉淀物的厌氧浓缩培养物，可以脱氯广泛的高氯化多氯联苯(PCB)。这些培养物是从马萨诸塞州勒诺克斯Housatonic河被Aroclor 1260污染的沉积物中开发出来的。沉淀物浆液中加入2，6-二溴联苯以刺激过程N的脱氯(主要是间位脱氯)，通过连续转移(10%)到最低限度的介质逐渐去除沉淀物。这些培养物生长在丙酮酸、丁酸盐或醋酸盐+11上，气相色谱-电子捕获检测器分析表明，在22-24℃的温度下，这些培养物通过脱氯过程N对50-500 mU g/ml的Aroclor 1260进行广泛的脱氯。第八次无沉淀物转移的三重培养物在110天内将Aroclor 1260中76%的六至五氯联苯(250 mU/ml)脱氯为三至五氯联苯。至少多氯联苯同系物是这种脱氯的底物，所有这些多氯联苯都是在两个环上进行氯化的，其中47个环含有六个或更多的氯。为了表征细菌的多样性，我们用真细菌引物从醋酸盐加H-2限制性片段长度的培养上提取的DNA中扩增并克隆了16S rRNA基因。107个克隆的多态性分析表明，存在类塔维埃拉β蛋白细菌、类地质杆菌、假单胞菌、各种梭状芽胞杆菌、类杆菌、脱卤球菌属，以及未分类的真细菌。我们开发了高度丰富、健壮、稳定、无沉淀物的培养物，可以广泛地脱氯高度氯化的商业多氯联苯混合物，这是该领域前所未有的重大突破。它将使人们能够深入研究对环境中发生的主要多氯联苯、脱氯过程负责的生物体和基因，并可能导致有效的补救应用。
We have developed sediment-free anaerobic enrichment cultures that dechlorinate a broad spectrum of highly chlorinated polychlorinated biphenyls (PCBs). The cultures were developed from Aroclor 1260-contaminated sediment from the Housatonic River in Lenox, MA. Sediment slurries were primed with 2,6-dibromo-biphenyl to stimulate Process N dechlorination (primarily meta dechlorination), and sediment was gradually removed by successive transfers (10%) to minimal medium. The cultures grow on pyruvate, butyrate, or acetate plus 11, Gas chromatography-electron capture detector analysis demonstrated that the cultures extensively dechlorinate 50 to 500 mu g/ml of Aroclor 1260 at 22 to 24 degrees C by Dechlorination Process N. Triplicate cultures of the eighth transfer without sediment dechlorinated 76% of the hexa- through nonachlorobiphenyls in Aroclor 1260 (250 mu g/ml) to tri- through pentachlorobiphenyls in 110 days. At least 64 PCB congeners, all of which are chlorinated on both rings and 47 of which have six or more chlorines, were substrates for this dechlorination. To characterize the bacterial diversity in the enrichments, we used eubacterial primers to amplify and clone 16S rRNA genes from DNA extracted from cultures grown on acetate plus H-2 Restriction fragment length polymorphism analysis of 107 clones demonstrated the presence of Thauera-like Betaproteobacteria, Geobacterlike Deltaproteobacteria, Pseudomonas species, various Clostridiales, Bacteroidetes, Dehalococcoides of the Chloroflexi group, and unclassified Eubacteria. Our development of highly enriched, robust, stable, sediment-free cultures that extensively dechlorinate a highly chlorinated commercial PCB mixture is a major and unprecedented breakthrough in the field. It will enable intensive study of the organisms and genes responsible for a major PCB, dechlorination process that occurs in the environment and could also lead to effective remediation applications.