Dehalobacter restrictus gen. nov. and sp. nov., a strictly anaerobic bacterium that reductively dechlorinates tetra-and trichloroethene in an anaerobic respiration

• Published in: Archives of microbiology Vol. 169; no. 4; pp. 313 - 321
• Main Authors: HOLLIGER, C, HAHN, D, HARMSEN, H, LUDWIG, W, SCHUMACHER, W, TINDALL, B, VAZQUEZ, F, WEISS, N, ZEHNDER, A. J. B
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.04.1998; Berlin
• Subjects: Anaerobiosis; Bacteria, Anaerobic - genetics; Bacteria, Anaerobic - metabolism; Bacteria, Anaerobic - ultrastructure; Bacteriology; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; Cell Division - physiology; Dehalobacter restrictus; Fundamental and applied biological sciences. Psychology; Isolation and description; Laboratorium voor Microbiologie; Microbiological Laboratory; Microbiologie; Microbiology; Mission oriented research; Oxidation-Reduction; Phylogeny; RNA, Ribosomal, 16S - analysis; RNA, Ribosomal, 16S - genetics; Systematics; Tetrachloroethylene - metabolism; trichloroethene; Trichloroethylene - metabolism; Anaerobiosis; New genus; Description; Taxonomy; Organic perhalocompound; Detoxication; Genotype; Ethylene(tetrachloro); Characterization; Dechlorination; Phenotype; Chlorine Organic compounds; Chlorocarbon; Bacteria; New species; Ethylene(trichloro)
• ISSN: 0302-8933; 1432-072X
• DOI: 10.1007/s002030050577

The highly enriched anaerobic bacterium that couples the reductive dechlorination of tetrachloroethene to growth, previously referred to as PER-K23, was obtained in pure culture and characterized. The bacterium, which does not form spores, is a small, gram-negative rod with one lateral flagellum. It utilized only H2 as an electron donor and tetrachloroethene and trichloroethene as electron acceptors in an anaerobic respiration process; it could not grow fermentatively. Acetate served as a carbon source in a defined medium containing iron as the sole trace element, the two vitamins thiamine and cyanocobalamin, and the three amino acids arginine, histidine, and threonine. The cells contained menaquinones and b-type cytochromes. The G+C content of the DNA was 45.3 +/- 0.3 mol%. The cell wall consisted of type-A3gamma peptidoglycan with ll-diaminopimelic acid and one glycine as an interpeptide bridge. The cells are surrounded by an S-layer; an outer membrane was absent. Comparative sequence analysis of the 16S rRNA sequence showed that PER-K23 is related to gram-positive bacteria with a low G+C content of the DNA. Based on the cytological, physiological, and phylogenetic characterization, it is proposed to affiliate the isolate to a new genus, Dehalobacter, with PER-K23 as the type strain of the new species Dehalobacter restrictus.