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 2C6-43(T), was isolated and characterized taxonomically by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 2C6-43(T) belongs to the family Bogoriellaceae, class Actinobacteria, and is related most closely to Georgenia soli CC-NMPT-T3(T) (98.8 % sequence similarity), Georgenia muralis 1A-C-T (97.6 %), Georgenia thermotolerans TT02-04(T) (96.8 %), Georgenia ruanii YIM 004(T) (96.6 %) and Georgenia halophila YIM 93316(T) (96.0 %). The G+C content of the genomic DNA of strain 2C6-43(T) was 66.2 mol%. Sugars from whole-cell hydrolysates found in strain 2C6-43(T) were rhamnose, ribose and galactose. The menaquinone MK-8(H-4) was detected as the predominant quinone. Polar lipid analysis of 2C6-43(T) 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 2C6-43(T). A fatty acid profile with anteiso-C-15:0, iso-C-15:0 and C-16:0 as the major components supported the affiliation of strain 2C6-43(T) to the genus Georgenia. However, the DNA-DNA relatedness between strain 2C6-43(T) 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 2C6-43(T) could be clearly differentiated from its phylogenetic neighbours on the basis of some phenotypic, genotypic and chemotaxonomic features. Therefore, strain 2C6-43(T) 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 2C6-43(T) (=KCTC 19801(T)=JCM 17459(T)).