Brevibacterium daeguense sp. nov., a nitrate-reducing bacterium isolated from a 4-chlorophenol enrichment culture

Abstract

A Gram-reaction-positive, non-spore-forming, aerobic actinobacterial strain (2C6-41T) was isolated from the activated sludge from an industrial wastewater treatment plant in Daegu, South Korea. Its taxonomic position was investigated by using a polyphasic approach. On the basis of 16S rRNA gene sequence similarity, closest phylogenetic relatives to strain 2C6-41T were Brevibacterium pityocampae DSM 21720T (97.2%), Brevibacterium salitolerans KCTC 19616T (96.7%), Brevibacterium album KCTC 19173T (96.2%) and Brevibacterium samyangense KCCM 42316T (96.2%). The DNA G+C content of strain 2C6-41T was 66.4 mol%. Chemotaxonomic data, which included MK-8(H2) as the major menaquinone; meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids; ribose, mannose and glucose as major cell-wall sugars; and anteiso-C15: 0, anteiso-C17: 0, C16: 0 and iso-C15: 0 as major fatty acids, supported the affiliation of strain 2C6-41T to the genus Brevibacterium. The aromatic ring cleavage enzyme catechol 1,2-dioxygenase was not detected in strain 2C6-41T, but catechol 2,3-dioxygenase was detected. The results of physiological and biochemical tests, and the low level of DNA-DNA relatedness to the closest phylogenetic relative enabled strain 2C6-41T to be differentiated genotypically and phenotypically from recognized species of the genus Brevibacterium. The isolate is therefore considered to represent a novel species in the genus Brevibacterium, for which the name Brevibacterium daeguense sp. nov. is proposed. The type strain is 2C6-41T (5KCTC 19800T5JCM 17458T).