Sphingomonas aerophila sp nov and Sphingomonas naasensis sp nov., isolated from air and soil, respectively

Two strains, designated 5413J-26(T) and KIS18-15(T), were isolated from the air and forest soil, respectively, in South Korea. Cells of the two strains were Gram-stain-negative, aerobic, polarflagellated and rod-shaped. According to the phylogenetic tree, strains 5413J-26(T) and KIS18-15(T) fell into the cluster of Sphingomonas sensu stricto. Strain 5413J-26(T) showed the highest sequence similarities with Sphingomonas trueperi LMG 2142(T) (96.6%), Sphingomonas molluscorum KMM 3882(T) (96.5%), Sphingomonas azotifigens NBRC 15497(T) (96.3%) and Sphingomonas pituitosa EDIVT (96.1%), while strain KIS18-15(T) had the highest sequence similarity with Sphingomonas soli T5-04(T) (96.8%), Sphingomonas pituitosa EDIVT (96.6%), Sphingomonas leidyi ATCC 15260(T) (96.6%), Sphingomonas asaccharolytica NBRC 15499(T) (96.6%) and Sphingomonas koreensis JSS26(T) (96.6%). The 16S rRNA gene sequence similarity between Strains 5413J-26(T) and KIS18-15(T) was 95.4%. Ubiquinone 10 was the predominant respiratory quinone and homospermidine was the major polyamine. The major polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and several unidentified phospholipids and lipids. The main cellular fatty acids (>10% of the total fatty acids) of strain 5413J-26(T) were summed feature 8 (C-18:1 omega 6c and/or C-18:1 omega 7c), summed feature 3 (C-16:1 omega 7c and/or iso-C-15:0 2-OH) and C-14:0 2-OH, and those of strain KIS18-15(T) were summed feature 8 and C-16:0. Based on the results of 16S rRNA gene sequence analysis, and physiological and biochemical characterization, two novel species with the suggested names Sphingomonas aerophila sp. nov. (type strain 5413J-26(T)=KACC 16533(T)=NBRC 108942(T)) and Sphingomonas naasensis sp. nov. (type strain KIS18-15(T)=KACC 16534(T)=NBRC 108943(T)) are proposed.