Description and genome analysis of Luteimonas viscosa sp. nov., a novel bacterium isolated from soil of a sunflower field.

Strain XBU10 was isolated from a soil sample of a sunflower plot in Inner Mongolia, China. The isolate was a Gram-stain-negative, aerobic, non-motile, rod-shaped bacterium, and its colonies were bright yellow in colour. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain XBU10 belonged to the genus Luteimonas of the family Lysobacteraceae and was most closely related to Luteimonas panaciterrae Gsoil 068 (97.8%), Luteimonas marina FR1330 (97.6%), Luteimonas aquatica RIB1-20 (97.4%) and Luteimonas huabeiensis HB2 (97.2%). Growth occurred at 4-40 °C (optimum, 28-30 °C), with 0-5.0% (w/v) NaCl (optimum, 0.5%) and at pH 6.0-10.0 (optimum, pH 7.0 - 8.0). The chemotaxonomic characteristics of strain XBU10, which had Q-8 as its predominant quinone and iso-C ω9c, iso-C, iso-C and iso-C as its major fatty acids, were consistent with classification in the genus Luteimonas. The polar lipid profile of strain XBU10 comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unidentified phospholipid, two unidentified aminophospholipids and three unidentified polar lipids. The genome of strain XBU10 was 4.17 Mbp with a G + C content of 69.9%. Its genome sequence showed genes encoding alkaline phosphatase and catalase. Protein-coding genes related to carbohydrate-active enzymes were also observed. Average nucleotide identity (ANI) values between XBU10 and other species of the genus Luteimonas were found to be low (ANIm < 88.0%, ANIb < 85.0% and OrthoANIu < 85.0%). Furthermore, digital DNA-DNA hybridization (dDDH) and average amino acid identity (AAI) values between strain XBU10 and the closely related species ranged from 20.3 to 28.9% and from 64.2 to 82.3%, respectively. Based on the results of our phylogenetic, phenotypic, genotypic and chemotaxonomic analyses, it is concluded that strain XBU10 represents a novel species within the genus Luteimonas, for which the name Luteimonas viscosa sp. nov. is proposed. The type strain is XBU10 (= CGMCC 1.12158 = KCTC 23878).