International Journal of Systematic and Evolutionary Microbiology, Vol 52, 801-807, Copyright © 2002 by Society for General Microbiology

Reclassification of Clostridium hydroxybenzoicum as Sedimentibacter hydroxybenzoicus gen. nov., comb. nov., and description of Sedimentibacter saalensis sp. nov

A. Breitenstein, J. Wiegel, C. Haertig, N. Weiss, J. R. Andreesen and U. Lechner
Institut fur Mikrobiologie, Martin-Luther-Universitat Halle, Kurt-Mothes-Strasse 3, 06099 Halle, Germany

Strain ZF2(T), isolated from freshwater sediment, is a motile, rod-shaped, Gram-positive, endospore-forming, amino acid- and pyruvate-utilizing, anaerobic bacterium. It requires yeast extract for growth. Carbohydrates are not utilized. The optimal temperature and pH for growth are 37 degrees C and 6.8--7.3, respectively. The G+C content of the DNA is 34.0 mol%. A 16S rDNA sequence analysis of strain ZF2(T) revealed that the highest similarity (94.4%) was shared with Clostridium hydroxybenzoicum JW/Z-1(T). Strain ZF2(T), however, was not able to carboxylate phenol or to decarboxylate 4-hydroxybenzoate, which are characteristic properties of strain JW/Z-1(T). The degree of 16S rDNA relatedness, together with the physiological and chemotaxonomic properties, suggest that strain ZF2(T) represents a novel species that is clearly distinct from Clostridium hydroxybenzoicum JW/Z-1(T). In a phylogenetic dendrogram, both strains form a separate cluster that is peripherally associated with the Peptostreptococcus group (cluster XIII) of the clostridia and the lineage of Helcococcus kunzii. Strains ZF2(T) and JW/Z-1(T) show a somewhat deeper branching from the cluster XII clostridia Clostridium purinolyticum and Clostridium acidiurici. The latter strains possessed the closest 16S rDNA similarity (between 88.4 and 90.7%), but were clearly separated by phenotypic markers. Therefore, a new genus, Sedimentibacter gen. nov., is described, comprising Sedimentibacter hydroxybenzoicus gen. nov., comb. nov., as the type species of the genus, with JW/Z-1(T) (=ATCC 51151(T)=DSM 7310(T)) as the type strain, and the novel species Sedimentibacter saalensis sp. nov., with strain ZF2(T) (=DSM 13558(T)=ATCC BAA-283(T)) as the type strain.