Quadrisphaera oryzae sp. nov., an endophytic actinomycete isolated from leaves of rice plant (Oryza sativa L.)

Quadrisphaera setariae sp. nov., polyphosphate-accumulating bacterium occurring as tetrad or aggregate cocci and isolated from Setaria viridis

A Gram-stain-positive, orange-pigmented, aerobic, cocci (occurring in tetrads), non-spore-forming, non-motile bacterium, designated as DD2AT, was isolated from Setaria viridis collected at Dongguk University, Republic of Korea. Phylogenetic analysis based on the 16S rRNA gene revealed that strain DD2AT was most closely related to type strains of the genus Quadrisphaera . Strain DD2AT showed the highest 16S rRNA gene sequence similarities to Quadrisphaera oryzae TBRC 8486T (99.4 %) and Quadrisphaera granulorum JCM 16010T (98.8 %). Strain DD2AT also showed auto-aggregation ability. The digital DNA–DNA hybridization values between strain DD2AT and the reference strains, Q. oryzae TBRC 8486T and Q. granulorum JCM 16010T were 31.1 and 27.4 %, respectively. The average nucleotide identity values between strain DD2AT and Q. oryzae TBRC 8486T and Q. granulorum JCM 16010T were 86.3 and 84.1 %, respectively. The major polar lipids of strain DD2AT were diphosphatidylglycerol and phosphatidylglycerol. The major cellular fatty acid of strain DD2AT was anteiso-C15 : 0. The cell-wall peptidoglycan contained meso-diaminopimelic acid (which is a diagnostic cell-wall diamino acid), alanine and glutamic acid. The respiratory quinones was found to be menaquinone-8. The DNA G+C content of strain DD2AT was 74.8 mol%. On the basis of the findings of genotypic, phenotypic, chemotaxonomic and phylogenetic analyses, strain DD2AT was considered to represent a novel member in the genus Quadrisphaera , for which the name Quadrisphaera setariae sp. nov. is proposed. The type strain of Quadrisphaera setariae is DD2AT (=KACC 21165T=NBRC 113770T).

Microbispora oryzae sp. nov., isolated from leaves of rice plant (Oryza sativa L.)

An endophytic actinomycete, designated strain RL4-1S^T, was isolated from surface-sterilized leaves of rice plant (Oryza sativa L.) collected from Buri Rum province, Thailand. Its taxonomic status was determined using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequences showed that the strain RL4-1S^T belongs to the genus Microbispora and is most closely related to Microbispora rosea subsp. rosea ATCC 12950^T (98.5%). The strain forms pairs of spores on short sporophores borne on the aerial mycelium. Polar lipid profile of strain RL4-1S^T is diphosphatidylglycerol, hydroxy-phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, ninhydrin-positive glycophospholipid, two unidentified phospholipids, an unidentified aminolipid, and an unidentified glycolipid. MK-9(H₄), MK-9(H₂), and MK-9 are major menaquinones of this organism. The predominant cellular fatty acids are iso-C_16:0, C_17:0 and C_16:0. Strain RL4-1S^T contains meso-diaminopimelic acid, glucose, madurose and ribose in whole-cell hydrolysates. The draft genome of strain RL4-1S^T consists of 7.46 Mbp and has a G + C content 71.2 mol%. Digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain RL4-1S^T with Microbispora rosea subsp. rosea ATCC 12950^T are 26.0% and 80.7%, respectively. Based on data of genotypic, phenotypic, phylogenetic and chemotaxonomic analysis, strain RL4-1S^T represents a novel species of the genus Microbispora, for which the name Microbispora oryzae sp. nov. is proposed. The type strain is RL4-1S^T (= TBRC 14817^T = NBRC 115115^T).