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

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(H₄) 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).