Freedman D L, Gossett J M
School of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853-3501.
Appl Environ Microbiol. 1989 Sep;55(9):2144-51. doi: 10.1128/aem.55.9.2144-2151.1989.
A biological process for remediation of groundwater contaminated with tetrachloroethylene (PCE) and trichloroethylene (TCE) can only be applied if the transformation products are environmentally acceptable. Studies with enrichment cultures of PCE- and TCE-degrading microorganisms provide evidence that, under methanogenic conditions, mixed cultures are able to completely dechlorinate PCE and TCE to ethylene, a product which is environmentally acceptable. Radiotracer studies with [14C]PCE indicated that [14C]ethylene was the terminal product; significant conversion to 14CO2 or 14CH4 was not observed. The rate-limiting step in the pathway appeared to be conversion of vinyl chloride to ethylene. To sustain reductive dechlorination of PCE and TCE, it was necessary to supply an electron donor; methanol was the most effective, although hydrogen, formate, acetate, and glucose also served. Studies with the inhibitor 2-bromoethanesulfonate suggested that methanogens played a key role in the observed biotransformations of PCE and TCE.
只有当转化产物对环境可接受时，用于修复被四氯乙烯（PCE）和三氯乙烯（TCE）污染的地下水的生物过程才能应用。对降解PCE和TCE的微生物富集培养物的研究表明，在产甲烷条件下，混合培养物能够将PCE和TCE完全脱氯为乙烯，乙烯是一种对环境可接受的产物。用[14C]PCE进行的放射性示踪研究表明，[14C]乙烯是终产物；未观察到向14CO2或14CH4的显著转化。该途径中的限速步骤似乎是氯乙烯向乙烯的转化。为了维持PCE和TCE的还原脱氯，必须提供电子供体；甲醇是最有效的，尽管氢气、甲酸盐、乙酸盐和葡萄糖也可以起到作用。用抑制剂2-溴乙烷磺酸盐进行的研究表明，产甲烷菌在观察到的PCE和TCE的生物转化中起关键作用。
