Reductive Dehalogenation of Trichloroacetic Acid by Trichlorobacter thiogenes gen. nov., sp. nov

Abstract

A bacterium able to grow via reductive dechlorination of trichloroacetate was isolated from anaerobic soil enrichments. The isolate, designated strain K1, is a member of the δ proteobacteria and is related to other known sulfur and ferric iron reducers. In anaerobic mineral media supplemented with acetate and trichloroacetate, its doubling time was 6 h. Alternative electron donor and acceptors were acetoin and sulfur or fumarate, respectively. Trichloroacetate dehalogenation activity was constitutively present, and the dechlorination product was dichloroacetate and chloride. Trichloroacetate conversion seemed to be coupled to a novel sulfur-sulfide redox cycle, which shuttled electrons from acetate oxidation to trichloroacetate reduction. In view of its unique physiological characteristics, the name Trichlorobacter thiogenes is suggested for strain K1.

Comparison of 16S rRNA, nifD, recA, gyrB, rpoB and fusA genes within the family Geobacteraceae fam. nov.

“…Desulfuromonas thiophila DSM 8987 T , Desulfuromusa bakii DSM 7345 T , Desulfuromusa succinoxidans DSM 8270 T , Geobacter bremensis DSM 12179 T , Geobacter pelophilus DSM 12255 T , Pelobacter acetylenicus DSM 3246 T , Pelobacter massiliensis DSM 6233 T and Pelobacter venetianus DSM 2394 T were obtained from the DSMZ. Trichlorobacter thiogenes K1 T was obtained from the laboratory of James Tiedje (De Wever et al, 2000).…”

“…Pelobacter acidigallici, Pelobacter carbinolicus, Pelobacter venetianus and Pelobacter massiliensis were grown in DSM medium 293 with 0?68 g gallic acid l 21 , 0?9 g 2,3-butanediol l 21 , 1 g polyethylene glycol l 21 and 0?5 g pyrogallol l 21 , respectively. Trichlorobacter thiogenes was grown in basal salts medium (De Wever et al, 2000) with 10 mM fumarate as electron acceptor and 5 mM acetate as electron donor and 0?36 g NaS.9H 2 O l 21 as reductant at 25 uC for DNA sequence studies.…”

Biodiversity of Dehalorespiring Bacteria with Special Emphasis on Polychlorinated Biphenyl/Dioxin Dechlorinators

“…T =ATCC BAA-34 T =JCM 14045 T ), which is a trichloroacetic acid dechlorinator 36) , has been transferred to the genus Geobacter as Geobacter thiogenes 97) .…”

Geobacter luticola sp. nov., an Fe(III)-reducing bacterium isolated from lotus field mud

“…Although this group appears to be versatile, among the 17 species of the genus Geobacter published to date, only four species were reported to be capable of utilizing nitrate as an electron acceptor, namely Geobacter argillaceus (Shelobolina et al, 2007), Geobacter lovleyi (Sung et al, 2006), Geobacter metallireducens (Lovley et al, 1993) and Geobacter thiogenes (De Wever et al, 2000;Nevin et al, 2007).…”