Alteribacter keqinensis sp. nov., a moderately halophilic bacterium isolated from a soda lake

A Gram-stain-positive, aerobic, endospore-forming and rod-shaped bacterium (KQ-3(T)), which grew at 10-45 degrees C (optimum 35 degrees C), pH 8.0-10.5 (optimum pH 9.0) and in the presence of 0-16% (w/v) NaCl (optimum 3.0%), was isolated from a soda lake and identified as representing a novel species using a polyphasic taxonomic approach. Strain KQ-3(T) was catalase-positive, oxidase-negative and non-motile. Phylogenetic analysis based on 16S rRNA gene sequence affiliated KQ-3(T) to the genus Alteribacter and showed the highest similarities to Alteribacter natronophilus M30(T) (97.90%), Alteribacter aurantiacus K1-5T (97.84%) and Alteribacter populi FJAT-45347(T) (97.22%). Digital DNA-DNA hybridization and average nucleotide identity analyses revealed that KQ-3(T) displayed 21.4 and 72.81% genomic DNA relatedness with the most closely related strain, A. natronophilus M30T, respectively. KQ-3(T) contained all of the conserved signature indels that are specific for members of the genus Alteribacter. The DNA G+C content was 45.03 mol%. The cell-wall peptidoglycan contained meso-diaminopimelic acid and the polar lipids consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and one unidentified phospholipid. The predominant menaquinone was MK-7 (100%) and the major fatty acids (>10 %) comprised anteiso-C-15: 0, iso-C-15:0 and iso-C-16:0. Based on the data from the current polyphasic studies, KQ-3(T) represents a novel species of the genus Alteribacter, for which the name Alteribacter keqinensis sp. nov. is proposed. The type strain is KQ-3(T) (=ACCC 61799(T)=KCTC 33933(T)).