Microbacterium salitolerans sp. nov., isolated from saline soil

Strain G2-8^T was isolated from a soil sample collected from the saline area of Baodi District in Tianjin City. The isolate was a Gram-stain-positive, aerobic, non-motile, rod-shaped bacterium, and its colonies were round, raised, pale yellow, with a smooth surface, regular and clean edges. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain G2-8^T belonged to the genus <i>Microbacterium</i> and shared the highest sequence similarity with <i>Microbacterium excoecariae</i> CBS5P-1^T (98.5%), followed by <i>Microbacterium amylolyticum</i> N5^T (98.2%), <i>Microbacterium gubbeenense</i> DSM 15944^T (98.1%), <i>Microbacterium indicum</i> BBH6^T (97.5%), <i>Microbacterium suaedae</i> YZYP 306^T (97.5%) and <i>Microbacterium karelineae</i> TRM 80801^T (97.4%). Phylogenomic analysis showed that strain G2-8^T was related to members of the genus <i>Microbacterium</i> and represented an independent lineage. Growth occurred at 4-40 °C (optimum, 28 °C), up to 13.0% (w/v) NaCl (optimum, 0-2.0%) and pH 6.0-10.0 (optimum, pH 8.0). Its main fatty acids were anteiso-C_{15 : 0} and anteiso-C_{17 : 0}. The major respiratory quinone of strain G2-8^T was MK-10, MK-11 and MK-12. The polar lipid profile of strain G2-8^T comprised diphosphatidylglycerol, phosphatidylglycerol and two unidentified polar lipids. The genome of strain G2-8^T was 3.46 Mbp with a G+C content of 69.7 mol%. The average nucleotide identity (ANI) values between strain G2-8^T and other related species of the genus <i>Microbacterium</i> were found to be low (ANIm <84.8%, ANIb <77.2% and OrthoANIu <79.6%). Furthermore, the digital DNA-DNA hybridization and average amino acid identity values between strain G2-8^T and the closely related species ranged from 19.0 to 24.2% and from 65.9 to 79.6%, respectively. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain G2-8^T represents a novel species of the genus <i>Microbacterium</i>, for which the name <i>Microbacterium salitolerans</i> sp. nov. is proposed. The type strain is G2-8^T (=KCTC 49757^T=GDMCC 1.2353^T).