Citricoccus alkalitolerans sp. nov., a novel actinobacterium isolated from a desert soil in Egypt

Abstract

An actinobacterium, strain YIM 70010T, which was isolated from a desert soil sample collected in Egypt, was subjected to a polyphasic taxonomy study. The organism was alkalitolerant and its optimum growth occurred at pH 8.0-9.0. The isolate contained chemotaxonomic markers that were characteristic of the genus Citricoccus, i.e. the peptidoglycan type Lys-Gly-Glu (variation A4α), the predominant menaquinone MK-9(H2) and a polar lipid profile consisting of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and two unknown glycolipids. The major fatty acids were anteiso-C15:0 and iso-C15:0. The G+C content of the genomic DNA was 63.8 mol%. Strain YIM 70010T exhibited a 16S rRNA gene sequence similarity of 99.6% and DNA-DNA relatedness value of 56% with Citricoccus muralis DSM 14442T. The phenotypic characteristics and DNA-DNA relatedness data indicate that strain YIM 70010T can be distinguished from C. muralis (DSM 14442T). Therefore, on the basis of the polyphasic taxonomic data presented, a novel species of the genus Citricoccus, Citricoccus alkalitolerans sp. nov. (type strain, YIM 70010T=CCTCC AA 203008T=DSM 15665T=KCTC 19012T) is proposed.