Novosphingobium kaempferiae sp. nov., a phosphate-solubilizing bacterium isolated from stem of Kaempferia marginata Carey

Abstract

A Gram-stain-negative, aerobic, rod-shaped, non-spore-forming and yellow-pigment-producing bacterium, designated as Sx8-5T, was isolated from stem tissue of Kaempferia marginata Carey in Kanchanaburi Province, Thailand. The strain exhibited tricalcium phosphate solubilizing activity. Its taxonomic position was investigated using a polyphasic approach. Sx8-5T grew at 25–37 °C (optimum 30 °C), pH 6–9 (optimum 7) and with 0 and 1% NaCl (optimum 0 %). According to the 16S rRNA gene phylogeny, Sx8-5T represents a member of genus Novosphingobium and shared the highest sequence similarities to Novosphingobium barchaimii LL02T of 99.4 % and shared sequence similarities with other species of the genus Novosphingobium of less than 99.4 %. The whole-genome size was 5.7 Mb, comprised of one contig, with a DNA G+C content of 66 %. The average nucleotide identity using BLASTn (ANIb) or MUMMER (ANIm) values for whole genome comparisons between Sx8-5T and Novosphingobium barchaimii LL02T and six closely related type strains were 72.33–82.14 % and 83.82–87.38 %, respectively, and the digital DNA–DNA hybridization (dDDH) values ranged from 21.0 to 28.6% when compared with the type strains of the members of the genus Novosphingobium . Major fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1  ω6c), C16 : 0 and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), respectively. Polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, unidentified phospholipids and unidentified polar lipids. The major isoprenoid quinone was Q-10. According to results obtained using a polyphasic approach, Sx8-5T represents a novel species of the genus Novosphingobium , the name Novosphingobium kaempferiae sp. nov. is proposed. The type strain is Sx8-5T (=JCM 35076T =TBRC 15600T).