Sphingomonas longa sp. nov., Sphingomonas mollis sp. nov. and Sphingomonas aurea sp. nov.: three novel Sphingomonas species isolated from soil

Three Gram-negative, aerobic and non-motile bacterial strains, BT552 , BT553 and KR1UV-12 , were isolated from soil samples in Gwangju-si and Gangneung-si, the Republic of Korea. Phylogenetic analysis based on 16S rRNA gene sequence showed that strains BT552 , BT553 and KR1UV-12 clustered to a distinct clade within the family (order , class ). The strains exhibited the highest genetic similarity with representatives of the genus ; moreover, strains BT552 and BT553 tightly clustered with DAPP-PG 224 (98.2 and 98.1 %) and JSS-7 (98.1 and 98.0 %), while strain KR1UV-12 clustered with DAPP-PG 224 (97.9%) and BH3 (97.8%), respectively. The major cellular fatty acids of all three strains were summed feature 8 (C ω7c/C ω6c), comprising 44.7, 46.4 and 48.5%. Additionally, their respiratory quinone is Q-10, and polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phospholipids, sphingolipid and phosphatidylcholine. They all grow well at an optimum temperature of 25 °C, at pH 7. The draft genomes of strains BT552 , BT553 and KR1UV-12 measures 4 035 561 bp, 3 941 714 bp and 3 418 792 bp, respectively, comprising 3 804 3648 and 3236 coding sequences and 50, 48 and 45 RNA genes. The average nucleotide identity analysis and digital DNA-DNA hybridization values between BT552 , BT553 and KR1UV-12 and closely related species range from 72.7 to 80.2% and 19.4 to 24.3%, respectively. Based on phenotypic, genotypic and chemotaxonomic data, these three strains BT552 , BT553 and KR1UV-12 represent three novel bacterial species within the genus for which the names sp. nov. (type strain BT552 = KCTC 82094 =NBRC 114993 ), sp. nov. (type strain BT553 =KCTC 82095 =NBRC 114994 ) and sp. nov. (type strain KR1UV-12 = KCTC 92959 = TBRC 18506 ) are proposed.