Nocardia coffeae sp. nov., an endophytic actinobacterium isolated from the root of Coffea arabica (L.).

The polyphasic taxonomic study of a novel endophytic actinobacterium strain (CA2R105T) was carried out. The strain formed fragmented substrate mycelium and showed chemotaxonomic properties typical of members of the genus Nocardia, i.e. the presence of mycolic acid and MK-8 (H4ω-cycl) in its cells. Strain CA2R105T exhibited the highest 16S rRNA gene sequence similarity to Nocardia jiangxiensis NBRC 101359T (99.2%). The genome-based taxonomic analysis revealed low average nucleotide identity-blast and digital DNA-DNA hybridization values (<93.7, and <65.2%, respectively) to its closest relative. Moreover, many different phenotypic characteristics were observed between strain CA2R105T and all related Nocardia-type strains. This taxonomic evidence suggested that strain CA2R105T should be judged as representing a novel species of the genus Nocardia and the name, Nocardia coffeae sp. nov. is proposed. The type strain is CA2R105T (=TBRC 11247T=NBRC 114292T).

Streptomyces acidipaludis sp. nov., an actinobacterium isolated from peat swamp forest soil.

An actinobacterium strain PLK6-54T was isolated from Lankwai peat swamp forest soil collected from Yala province, Thailand. Strain PLK6-54T exhibited morphological and chemotaxonomic properties described for the genus Streptomyces. It formed a spiral spore chain directly on aerial mycelium. Growth was observed between 20 and 40 °C and at pH 5-8. The maximum NaCl for growth was 2 % (w/v). ll-Diaminopimelic acid, arabinose and ribose were detected in the whole-cell hydrolysate. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositolmannoside were detected as the phospholipids. The major menaquinones were MK-10(H2) and MK-9(H6). The major cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0 and iso-C14 : 0. 16S rRNA gene sequence data supported the assignment of strain PLK6-54T to the genus Streptomyces and showed that Streptomyces rubidus NBRC 102073T (99.0 %) was the closest relative. Moreover, the average nucleotide identity-blast (85.5 %) and digital DNA-DNA hybridization (30.7 %) values reported between strain PLK6-54T and its closest neighbour were below the threshold values for delineation of a novel species. Strain PLK6-54T could be distinguished from related validly described Streptomyces species by several phenotypic properties. The combination of genotypic and phenotypic data indicated that strain PLK6-54T is representative of a novel species of the genus Streptomyces. The name Streptomyces acidipaludis sp. nov. is proposed for strain PLK6-54T. The type strain is PLK6-54T (=TBRC 11250T=NBRC 114297T).

Streptomyces endocoffeicus sp. nov., an endophytic actinomycete isolated from Coffea arabica (L.).

An aerobic, non-motile, Gram-stain positive actinomycete, designated strain CA3R110T, was isolated from the surface-sterilised root of Coffea arabica L. collected from Lampang Province, Thailand. 16S rRNA gene sequence analysis indicated that strain CA3R110T was a member of the genus Streptomyces and showed the closest similarities to Streptomyces buecherae AC541T (99.2%), followed by Streptomyces rapamycinicus NRRL B-5491T (99.1%), Streptomyces luteoverticillatus NBRC 3840T (99.1%), Streptomyces coerulescens NBRC 12758T (99.1%), and Streptomyces iranensis HM 35T (99.0%). Strain CA3R110T contained LL-diaminopimelic acid in cell peptidoglycan, MK-9(H6), and MK-9(H8) as major menaquinone, iso-C16:0, iso-C15:0, C16:0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannoside were detected in the cell. The chemotaxonomic characteristics possessed the typical properties of the genus Streptomyces. A low digital DNA-DNA hybridization (< 55.7%) and average nucleotide identity-blast (ANIb) (< 92.2%) values revealed that strain CA3R110T could be distinguished from any known Streptomyces species. With the differences in phenotypic and genotypic data, strain CA3R110T represents a novel species of genus Streptomyces, for which the name Streptomyces endocoffeicus sp. nov. is proposed. The type strain is CA3R110T (= TBRC 11245T = NBRC 114296T).

Streptomyces coffeae sp. nov., an endophytic actinomycete isolated from the root of Coffea arabica (L.).

An endophytic actinobacterium, designated strain CA1R205T, was isolated from the surface-sterilized root of Coffea arabica L. collected from Ratchaburi province, Thailand. The taxonomic position of this strain was evaluated using a polyphasic approach. The strain produced light yellowish brown to dark brownish black substrate mycelium and greyish white aerial mycelium. The spiral spore chains were produced directly on aerial mycelium. CA1R205T was found to have ll-diaminopimelic acid in the cell peptidoglycan, galactose, glucose, mannose and ribose as whole-cell reducing sugars, MK-10(H4), MK-9(H6), MK-10(H2), MK-9(H4), MK-10(H6) and MK-10(H8) as menaquinones and iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0 and C16 : 0 as major fatty acids. Diphosphatidylglycerol, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol were detected in the cells. These characteristics were consistent the typical chemotaxonomic properties of members the genus Streptomyces. The taxonomic affiliation at the genus level of this strain could be confirmed using its 16S rRNA gene sequence data. CA1R205T showed the highest 16S rRNA gene sequence similarity value to Streptomyces rapamycinicus NRRL B-5491T (98.9 %), followed by Streptomyces iranensis HM 35T (98.8 %). Digital DNA-DNA hybridization and average nucleotide identity-by blast (ANIb) values between CA1R205T and S. rapamycinicus NRRL B-5491T were 27.2 and 81.5 %, respectively. The DNA G+C content of genomic DNA was 70.7 mol%. Due to the differences in physiological, biochemical and genotypic data, CA1R205T could be discriminated from its closest neighbour. Thus, CA1R205T should be recognized as representing a novel species of the genus Streptomyces, for which the name Streptomyces coffeae sp. nov. is proposed. The type strain is CA1R205T (=TBRC 11244T=NBRC 114295T).