P113: 1.: Pyrosequence analysis of bacterial chloroethene-dechlorinating groundwater communities; 2.: Full-length haloalkane dehalogenase-encoding genes from environmental DNA using a genome-walking technique

1: The bacterial community structures of three tetrachloroethene-contaminated groundwater sites were analyzed and compared using pyrosequence data. For each site, the entire and the active bacterial populations were characterized by an independent sequence analysis of both PCR-amplified 16S rDNA and reverse transcribed 16S rRNA. The former industrial sites were selected to cover a broad range of contamination level of mainly tetrachloroethene. Before sampling the biomass, a long-term monitoring of the polluted sites revealed a significant in situ production of toxic by-products of the bacterial degradation of tetrachloroethene, such as trichloroethene, cis-dichloroethene and vinyl chloride.

2: Haloalkane dehalogenases (HLDs) are hydrolytic enzymes that cleave carbon-halogen bonds in various halogenated compounds. We developed degenerate oligonucleotide primers for haloalkane dehalogenase-encoding genes and used these to PCR-amplify large hld gene fragments using genomic DNA from the microbial community of a chlorinated-solvent-contaminated aquifer as a template. A genome-walking strategy was applied to obtain the sequence information of the missing upstream and downstream segments adjacent to the amplified hld gene fragments.

This research was supported by the Czech Science Foundation (grant P504/10/0137) and a RVO sponsorship (#61388971).