Chitinophaga horti sp. nov., Isolated from Garden Soil

A strictly aerobic Gram-negative bacterium, designated R8^T, isolated from garden soil in South Korea was subjected to a taxonomic study. The cells were non-spore-forming, oxidase-positive and catalase-negative, and non-motile rods (without flagella). Growth was observed between 10 °C and 40 °C (optimum, 30 °C) and between pH 6.0 and 9.0 (optimum, pH 7.0) and in the presence of 0%-1.5% (w/v) NaCl (optimum, 0%). The G + C content of the genomic DNA was 49.9% and the major isoprenoid quinone was found to be menaquinone-7. The major fatty acids of strain R8^T were iso-C_15:0, C_16:1 ω5c, and summed feature 3 (comprising iso-C_15:0 2-OH and/or C_16:1 ω7c/ω6c). Phosphatidylethanolamine was identified as a major polar lipid. Comparative 16S rRNA gene sequence analysis showed that strain R8^T had the highest 16S rRNA gene sequence similarity of 98.3% with Chitinophaga sedimenti TFL-3 ^T. Phylogenetic analyses using 16S rRNA gene sequences and concatenated 92 marker protein sequences revealed that strain R8^T formed a robust phylogenetic lineage with C. sedimenti within the genus Chitinophaga. Average nucleotide identity and digital DNA-DNA hybridization values of strain R8^T to Chitinophaga species were less than 77.9% and 21.1%, respectively. The phenotypic, phylogenetic, and chemotaxonomic properties support that strain R8^T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga horti sp. nov. is proposed. The type strain is R8^T (= KACC 19895 ^T = JCM 33215 ^T).