Taxonomic descriptions of Aeromicrobium duanguangcaii sp. nov., Aeromicrobium wangtongii sp. nov. and Aeromicrobium senzhongii sp. nov.

Six Gram-stain-positive, facultative anaerobic, nonmotile and rod-shaped strains, designated zg-Y50(T), zg-Y1362, zg-Y1379(T), zg-Y869, zg-629(T) and zg-Y636, were isolated from the intestinal contents of Marmota himalayana in Qinghai Province, PR China. Strains zg-Y50(T), zg-Y1379(T) and zg-629(T) exhibited the highest 16S rRNA gene sequence similarities of 99.2, 98.9 and 98.8 % to Aeromicrobium choanae 9 H-4(T), Aeromicrobium ginsengisoli JCM 14732(T) and Aeromicrobium flavum TYLN1T, respectively. Phylogenetic and phylogenomic analyses based on the 16S rRNA gene and genomic sequences, respectively, revealed that the six strains formed three distinct clades within the genus Aeromicrobium. The genome sizes of strains zg-Y50(T), zg-Y1379(T) and zg-629(T) were 3.1-3.7 Mb, with DNA G+C contents of 69.6-70.4mol%. Average nucleotide identity and digital DNA-DNA hybridization values between each novel strain and available members of the genus Aeromicrobium were all below species thresholds. All novel strains contained MK-9 (H-4) as the major menaquinone and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol as the polar lipids. The predominant fatty acid of the six isolates was C-18:1 omega 9c. The cell-wall peptidoglycan contained LL-diaminopimelic acid as the diagnostic diamino acid. Based on the results from this polyphasic taxonomic study, three novel species in the genus Aeromicrobium are proposed, namely, Aeromicrobium duanguangcaii sp. nov. (zg-Y50(T)= GDMCC 1.2981(T)=KCTC 49764(T)), Aeromicrobium wangtongii sp. nov. (zg-Y1379(T)= GDMCC 1.2982(T)=KCTC 49765(T)) and Aeromicrobium senzhongii sp. nov. (zg-629(T)= CGMCC 1.17414(T)=JCM 33888(T)).