Chitinophaga oryziterrae sp. nov., isolated from the rhizosphere soil of rice (Oryza sativa L.).

Abstract

A novel bacterial strain, YC7001(T), was isolated from the rhizosphere soil of rice collected at Jinju, Korea, and was characterized using a polyphasic approach. Cells of strain YC7001(T) were Gram-negative-staining, yellow-pigmented, rod-shaped, aerobic, heterotrophic and non-motile. Strain YC7001(T) grew optimally at 25-30 °C, pH 5.0-8.0 and degraded gelatin, cellulose and chitin. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YC7001(T) belonged to the genus Chitinophaga in the family Chitinophagaceae. The most closely related species were Chitinophaga sancti NBRC 15057(T) (96.9%), Chitinophaga ginsengisoli Gsoil 052(T) (95.9%), Chitinophaga pinensis DSM 2588(T) (95.7%), Chitinophaga filiformis IFO 15056(T) (95.7%) and Chitinophaga niabensis JS13-10(T) (95.0%). The DNA-DNA relatedness value of strain YC7001(T) with C. sancti NBRC 15057(T) was 15.2 ± 0.6%. Strain YC7001(T) contained MK-7 as the major menaquinone and homospermidine as the major polyamine. The major fatty acids of strain YC7001(T) were C(15:0) iso, C(16:1)ω5c and C(17:0) iso 3-OH. The polar lipids were phosphatidylethanolamine, unknown aminolipids and unknown lipids. The total genomic DNA G+C content was 41.3 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic analyses, strain YC7001(T) represents a novel species of the genus Chitinophaga, in the family Chitinophagaceae, for which the name Chitinophaga oryziterrae sp. nov. is proposed. The type strain is YC7001(T) ( = KACC 14533(T) = JCM 16595(T)).