Georgenia daeguensis sp. nov., isolated from 4-chlorophenol enrichment culture

Abstract

During screening for 4-chlorophenol-degrading micro-organisms in activated sludge from industrial wastewater treatment, a Gram-positive, rod-shaped, aerobic bacterial strain, designated 2C6-43T, was isolated and characterized taxonomically by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 2C6-43T belongs to the family Bogoriellaceae , class Actinobacteria , and is related most closely to Georgenia soli CC-NMPT-T3T (98.8 % sequence similarity), Georgenia muralis 1A-CT (97.6 %), Georgenia thermotolerans TT02-04T (96.8 %), Georgenia ruanii YIM 004T (96.6 %) and Georgenia halophila YIM 93316T (96.0 %). The G+C content of the genomic DNA of strain 2C6-43T was 66.2 mol%. Sugars from whole-cell hydrolysates found in strain 2C6-43T were rhamnose, ribose and galactose. The menaquinone MK-8(H4) was detected as the predominant quinone. Polar lipid analysis of 2C6-43T revealed diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol and phosphatidylglycerol. An aromatic compound ring cleavage enzyme of catechol 1,2-dioxygenase was detected but catechol 2,3-dioxygenase was not detected in 2C6-43T. A fatty acid profile with anteiso-C15 : 0, iso-C15 : 0 and C16 : 0 as the major components supported the affiliation of strain 2C6-43T to the genus Georgenia . However, the DNA–DNA relatedness between strain 2C6-43T and the type strains of five species of the genus Georgenia ranged from 17 to 40 %, clearly showing that the isolate constitutes a new genospecies. Strain 2C6-43T could be clearly differentiated from its phylogenetic neighbours on the basis of some phenotypic, genotypic and chemotaxonomic features. Therefore, strain 2C6-43T is considered to represent a novel species of the genus Georgenia , for which the name Georgenia daeguensis sp. nov. is proposed; the type strain is 2C6-43T ( = KCTC 19801T = JCM 17459T).