Pseudomonas rhizoryzae sp. nov., isolated from rice

Two yellow-pigmented, Gram-stain-negative and rod-shaped bacterial strains, designated as RY24^T and ZYY160, were isolated from rice. Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strains RY24^T and ZYY160 belonged to the genus Pseudomonas, and the 16S rRNA gene sequence similarity was 100 % The DNA homology between the two strains was 99.7 %. The 16S rRNA and rpoD gene sequences of the two strains showed highest similarity values to Pseudomonas oryzihabitans CGMCC 1.3392^T and Pseudomonas psychrotolerans DSM 15758^T (sharing 99.31 and 94.34 %, respectively). The major fatty acids of two strains were identified as summed feature 8 (C_18:1ω7c and/or C_18:1ω6c), C_16;0 and summed feature 3 (C_16:1ω7c and/or C_16:1ω6c), and the major respiratory quinone was identified as ubiquinone Q-9, which are typical chemotaxonomic features of members of the genus Pseudomonas. The genomic DNA G+C contents of strains RY24^T and ZYY160 were determined to be 64.25 and 64.21 mol%, respectively. The DNA-DNA relatedness and average nucleotide identity values between the two strains and their closely related type strains were below 36 and 90 %, which supported that RY24^T and ZYY160 represent a novel species in the genus Pseudomonas. Phylogenetic and chemotaxonomic evidence, together with phenotypic characteristics, showed that the two isolates constitute a novel species of the genus Pseudomonas. The type strain is RY24^T (JCM 33201^T=ACCC 61555^T), for which the name Pseudomonas rhizoryzae sp. nov. is proposed.