BIOREMEDIATION OF PCB CONTAMINATED SEDIMENTS IN THE ST LAWRENCE RIVER

这项建议的目标主要是基于我们之前的研究，以 开发强化厌氧降解底泥多氯联苯的技术 脱氯及其与好氧生物降解的结合 土著微生物种群，并决定其命运和生态 马塞纳附近圣劳伦斯河沉积物中多氯联苯的影响 超级基金网站。具体地说，我们将确定：(1)在 高污染沉积物中的现场脱氯；通过比较 研究通用汽车(GM)和雷诺汽车(Reynolds)的场地，我们将确定(A) 无论这些差异是由于微生物能力的差异还是 沉积物组成，(B)是什么决定了原地的终点 每个地点的脱氯，(C)如何在现场加速 生物转化；和(D)脱氯解毒的程度 人乳腺癌细胞MCF-7生长及儿茶酚胺的测定 在大鼠脑片中。实验将在实验室中进行 与天然沉积物的孵化研究。(2)阈值浓度 在点污染源以下的区域，可能会设置残留物 脱氯后的印刷电路板水平。我们还将确定脱氯 利用单一同系物分析、微生物生物量和群落的潜力 磷脂脂肪酸与16S rRNA杂交的特性 技巧。(3)如何维持和加强脱氯活动 挖出的沉积物。疏浚和封堵通常用于 修复受污染的地点和污染最严重的沉积物 通用汽车的厂址也将很快被疏浚。我们对疏浚哈德逊河的研究 沉积物显示，脱氯在早期阶段就停止了， 胶囊化和沉淀物不再含有脱氯作用 有机体。利用实验室中的模拟处置设施，我们将 确定脱氯活性变化的时间进程和 微生物生物量以及脱氯活性如何受 各种条件，包括水分含量和有机物。(4) 如何利用本土好氧降解脱氯产物 微生物。好氧多氯联苯降解菌将从 在脱氯研究中使用的相同沉积物的表层 使用联苯浓缩技术。然后分离出的菌株将被 确定它们对降解脱氯产品的有效性 在特定目标1和3的实验中积累的沉淀物。 降解特性和最佳降解条件将 也要有决心。我们还将确定有氧降解是否可以 在不接种分离物的情况下，在这些沉积物中诱导。

The goal of this proposal is, based largely on our previous studies, to develop techniques to degrade sediment PCBs by enhancing anaerobic dechlorination and combining it with aerobic biodegradation using indigenous microbial populations, and to determine the fate and ecological impact of sediment PCBs in the St. Lawrence River near the Massena Superfund site. Specifically, we will determine: (1) factors enhancing in situ dechlorination in highly contaminated sediments; through a comparative study of the General motors (GM) and Reynolds sites, we will determine (a) whether these differences are due to differences in microbial competence or sediment composition, (b) what determines the end point of in situ dechlorination at each site, (c) how to accelerate in situ biotransformation, and (d) the extent of detoxification by dechlorination with the assays of MCF-7 human breast cancer cell growth and catecholamines in rat brain slices. Experiments will be carried out in laboratory incubation studies with native sediments. (2) The threshold concentration in areas below the point source of contamination which may set the residual PCB level after dechlorination. We will also determine the dechlorination potential using single congener assays, microbial biomass and community characteristics with the phospholipid fatty acid and 16S rRNA hybridization techniques. (3) How to maintain and enhance dechlorinating activities in dredged sediments. Dredging and encapsulation are commonly used to remediate contaminated sites and the most heavily contaminated sediments at the GM site will also be dredged soon. Our studies of dredged Hudson River sediments showed that dechlorination ceased at an early stage after encapsulation and the sediments no longer harbored dechlorinating organisms. Using a simulated disposal facility in the laboratory, we will determine the time course of change in dechlorination activity and microbial biomass and also how dechlorination activity is affected by various conditions including the moisture content and organic matter. (4) how to degrade dechlorination products with indigenous aerobic microorganisms. Aerobic PCB-degrading bacteria will be isolation from the surface layers of the same sediments used in the dechlorination studies using the biphenyl-enrichment technique. The isolates will then be determined for their effectiveness to degrade the dechlorination products accumulated in sediments from experiments in Specific Aims 1 and 3. The degradation characteristics and optimum conditions for degradation will also be determined. We will also determine whether aerobic degradation can be induced in these sediments without inoculating isolates.