Microbacterium album sp. nov. and Microbacterium deserti sp. nov., two halotolerant actinobacteria isolated from...

Strains SYSU D8007^T and SYSU D8014^T were isolated from desert soil collected from Saudi Arabia. The two isolates were Gram-stain-positive, non-motile, aerobic and non-spore-forming. These strains were able to grow at 4-45 °C and in the presence of up to 8 % (w/v) NaCl. Strain SYSU D8007^T could grow at pH 6.0-10.0, and strain SYSU D8014^T at pH 5.0-10.0. They shared highest 16S rRNA gene sequence similarities with Microbacterium marinilacus YM11-607^T and Microbacterium paludicola US15^T. Menaquinones MK-11 and MK-12 were detected as the respiratory quinones. The polar lipid profiles of strains SYSU D8007^T and SYSU D8014^T consisted of diphosphatidylglycerol and phosphatidylglycerol, but differed in the number of unidentified glycolipids. Strain SYSU D8007^T contained anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0 as the predominant fatty acids, while strain SYSU D8014^T contained anteiso-C15 : 0 and anteiso-C17 : 0 as the major fatty acids (>10 %). While glucose, rhamnose and ribose were detected in strain SYSU D8007^T as the whole-cell sugars, galactose, glucose and rhamnose were present in strain SYSU D8014^T. The genomic DNA G+C content of strains SYSU D8007^T and SYSU D8014^T was 72.2 and 73.6 mol%, respectively. Based on phenotypic, genotypic and phylogenetic characteristics, it can be concluded that strains SYSU D8007^T and SYSU D8014^T represent two novel species of the genus Microbacterium, for which the names Microbacterium album sp. nov. and Microbacterium deserti sp. nov. are proposed, respectively. The type strains are SYSU D8007^T (=CGMCC 1.15794^T=KCTC 39990^T) and SYSU D8014^T (=CPCC 204619^T=KCTC39991^T).