Arthrobacter koreensis sp. nov., a novel alkalitolerant bacterium from soil

Abstract

Two Arthrobacter strains, CA15-8(T) and CA15-9, were isolated from soil, under alkali conditions, and characterized phenotypically, chemotaxonomically and genetically. These alkalitolerant organisms grew over a wide pH range (pH 7.0-12.0), with an optimum at pH 7.0-8.0. The mean G+C content of the DNA of these strains was 63+/-2 mol%. The strains contained MK-8(H(2)) and MK-9(H(2)) as the main respiratory quinones. The cell-wall peptidoglycan was Lys-Thr-Ala(2) and the whole-cell sugar was rhamnose. The major cellular fatty acids of the isolates were anteiso-C(15 : 0) and iso-C(15 : 0). A phylogenetic analysis, based on 16S rDNA sequence data, revealed that strains CA15-8(T) and CA15-9 formed an evolutionary lineage distinct from other Arthrobacter species. On the basis of morphological, physiological and chemotaxonomic characteristics, 16S rDNA sequence comparisons and DNA-DNA hybridization data, a novel species of Arthrobacter is proposed, namely Arthrobacter koreensis (type strain CA15-8(T)=KCTC 9922(T)=IFO 16787(T)).