title: Growth-substrate dependent dechlorination of 1,2-dichloroethane by a homoacetogenic bacterium.
abstract: A rod shaped, gram positive, non sporulating Acetobacterium strain was isolated that dechlorinated 1,2dichloroethane (1,2-DCA) to ethene at a dechlorination rate of up to 2 nmol Cl- min(-1) mg(-1) of protein in the exponential growth phase with formate (40 mM) as the substrate. Although with other growth substrates such as pyruvate, lactate, H2/CO2, and ethanol higher biomass productions were obtained, the dechlorination rate with these substrates was more than 10-fold lower compared with formate growing cells. Neither cell extracts nor autoclaved cells of the isolated Acetobacterium strain mediated the dechlorination of 1,2-DCA at significant rates. The addition of 1,2-DCA to the media did not result in increased cell production. No significant differences in corrinoid concentrations could be measured in cells growing on several growth-substrates. However, these measurements indicated that differences in corrinoid structure might cause the different dechlorination activity. The Acetobacterium sp. strain gradually lost its dechlorination ability during about 10 transfers in pure culture, probably due to undefined nutritional requirements. 16S rDNA analysis of the isolate revealed a 99.7% similarity with Acetobacterium wieringae. However, the type strains of A. wieringae and A. woodii did not dechlorinate 1,2-DCA.
authors.affiliation: Laboratory of Microbial Ecology and Technology, Faculty ofAgricultural and Applied Biological Sciences, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Wildeman
authors.forename: Anke
authors.initials: A
authors.lastname: Neumann
authors.forename: Gabriele
authors.initials: G
authors.lastname: Diekert
authors.forename: Willy
authors.initials: W
authors.lastname: Verstraete
mesh_terms: D045855:Acetobacterium / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000378:metabolism; D001673:Biodegradation, Environmental; D017077:Culture Media, Conditioned; D005025:Ethylene Dichlorides / Q000378:metabolism*; D005561:Formates / Q000378:metabolism; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000032:analysis
chemical_list: D017077:Culture Media, Conditioned; D005025:Ethylene Dichlorides; D005561:Formates; D012336:RNA, Ribosomal, 16S