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

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 degrees C and in the presence of up to 8% (w/v) NaCl. Strain SYSU D8007T 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-C-15:0, anteiso-C-17:0 and iso-C-16:0 as the predominant fatty acids, while strain SYSU D8014(T) contained anteiso-C-15:0 and anteiso-C-17:0 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 D8007T and SYSU D8014T 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)).