Metagenomics and qPCR analysis of aerobic metabolic TCE degradation

Chloroethenes are ubiquitous groundwater contaminants. While initially considered non-biodegradable, different pathways for both, anaerobic and aerobic degradation have been discovered in the last 30 years. While anaerobic, reductive, dechlorination of tetrachloroethene and trichloroethene (TCE) leads to the formation and therefore possible accumulation of the toxic intermediate products, dichloroethene and vinyl chloride, aerobic metabolic processes result in mineralization of the contaminants without the formation of stable intermediates. Therefore, productive aerobic degradation processes are at a considerable advantage over the reductive dechlorination processes. Aside from time consuming laboratory microcosm studies to observe biodegradation of contaminants under field conditions, the on-site potential for degradation processes can be assessed by molecular biological analysis, as demonstrated in recent years. Consortia from four batch enrichments and one groundwater microcosm were used to determine TCE degradation with chloride being the main product.