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 (2C6-41(T)) 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 2C6-41(T) were Brevibacterium pityocampae DSM 21720(T) (97.2 %), Brevibacterium salitolerans KCTC 19616(T) (96.7 %), Brevibacterium album KCTC 19173(T) (96.2 %) and Brevibacterium samyangense KCCM 42316(T) (96.2 %). The DNA G+C content of strain 2C6-41(T) was 66.4 mol%. Chemotaxonomic data, which included MK-8(H(2)) 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-C(15 : 0), anteiso-C(17 : 0), C(16 : 0) and iso-C(15 : 0) as major fatty acids, supported the affiliation of strain 2C6-41(T) to the genus Brevibacterium. The aromatic ring cleavage enzyme catechol 1,2-dioxygenase was not detected in strain 2C6-41(T), 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 2C6-41(T) 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 2C6-41(T) (=KCTC 19800(T) = JCM 17458(T)).