Marinimicrobium alkaliphilum sp. nov., an alkaliphilic bacterium isolated from soil and emended description of the genus Marinimicrobium.

Two Gram-stain-negative, rod-shaped bacterial strains, designated SW121 and W12, were isolated from a soil sample collected from Shanxi Province, China. The two strains were strictly aerobic, catalase-positive and oxidase-positive. Both strains grew at 6-42 °C (optimum, 30 °C), at pH 5.5-11.0 (optimum, pH 9.0) and in the presence of 0-15.0 % (w/v) NaCl (optimum, 2.0-3.0 %). The predominant cellular fatty acids of strain SW121 were C16 : 0, C18 : 1ω7c and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). Strain SW121 contained ubiquinone-8 as the sole respiratory quinone. Diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol were major polar lipids. The genomic DNA G+C content of strain SW121 was 58.5 mol%. Comparative analysis of 16S rRNA gene sequences revealed that strains SW121 and W12 showed the highest similarities to Marinimicrobium koreense DSM 16974(95.7 and 95.5 %, respectively). On the basis of phylogenetic inference and phenotypic characteristics, it is proposed that the two strains represent a novel species of the genus Marinimicrobium, for which the name Marinimicrobiumalkaliphilum sp. nov. is proposed. The type strain is SW121 (=CGMCC 1.16166=KCTC 62651).