Gerritse J, Renard V, Visser J, Gottschal J C
Department of Microbiology, University of Groningen, Haren, The Netherlands.
Appl Microbiol Biotechnol. 1995 Oct;43(5):920-8. doi: 10.1007/BF02431929.
Degradation of tetrachloroethene (perchloroethylene, PCE) was investigated by combining the metabolic abilities of anaerobic bacteria, capable of reductive dechlorination of PCE, with those of aerobic methanotrophic bacteria, capable of co-metabolic degradation of the less-chlorinated ethenes formed by reductive dechlorination of PCE. Anaerobic communities reductively dechlorinating PCE, trichloroethene (TCE) and dichloroethenes were enriched from various sources. The maximum rates of dechlorination observed for various chloroethenes in these batch enrichments were: PCE to TCE (341 mumol l-1 day-1), TCE to cis-dichloroethene (159 mumol l-1 day-1), cis-dichloroethene to chloroethene (99 mumol l-1 day-1) and trans-dichloroethene to chloroethene (22 mumol l-1 day-1). A mixture of these enrichments was inoculated into an anoxic fixed-bed upflow column. In this column PCE was converted mainly into cis-1,2-dichloroethene, small amounts of TCE and chloroethene, and chloride. Enrichments of aerobic methanotrophic bacteria were grown in an oxic fixed-bed downflow column. Less-chlorinated ethenes, formed in the anoxic column, were further metabolized in this oxic methanotrophic column. On the basis of analysis of chloride production and the disappearance of chlorinated ethenes it was demonstrated that complete degradation of PCE was possible by combining these two columns. Operation of the two-column system under various process conditions indicated that the sensitivity of the methanotrophic bacteria to chlorinated intermediates represented the bottle-neck in the sequential anoxic/oxic degradation process of PCE.
通过将能够对四氯乙烯（全氯乙烯，PCE）进行还原脱氯的厌氧细菌的代谢能力，与能够对由PCE还原脱氯形成的低氯代乙烯进行共代谢降解的好氧甲烷氧化细菌的代谢能力相结合，对四氯乙烯（PCE）的降解进行了研究。从各种来源富集了能够对PCE、三氯乙烯（TCE）和二氯乙烯进行还原脱氯的厌氧群落。在这些批次富集培养中，观察到的各种氯代乙烯的最大脱氯速率为：PCE转化为TCE（341 μmol·l⁻¹·天⁻¹）、TCE转化为顺式二氯乙烯（159 μmol·l⁻¹·天⁻¹）、顺式二氯乙烯转化为氯乙烯（99 μmol·l⁻¹·天⁻¹）以及反式二氯乙烯转化为氯乙烯（22 μmol·l⁻¹·天⁻¹）。将这些富集培养物的混合物接种到一个缺氧固定床上流式柱中。在这个柱中，PCE主要转化为顺式1,2 - 二氯乙烯、少量的TCE和氯乙烯以及氯离子。好氧甲烷氧化细菌的富集培养物在一个好氧固定床向下流式柱中生长。在缺氧柱中形成的低氯代乙烯在这个好氧甲烷氧化柱中进一步代谢。基于对氯离子产生和氯代乙烯消失的分析，证明了通过组合这两个柱可以实现PCE的完全降解。在各种工艺条件下对双柱系统的运行表明，甲烷氧化细菌对氯代中间体的敏感性是PCE顺序缺氧/好氧降解过程中的瓶颈。
