Streptomyces triticagri sp. nov. and Streptomyces triticirhizae sp. nov., two novel Actinobacteria isolated from the rhizosphere soil of wheat (Triticum aestivum L.)

Streptomyces profundus sp. nov., a novel marine actinobacterium isolated from deep-sea sediment of Madeira Archipelago, Portugal

A novel strain, MA3_2.13T, was isolated from deep-sea sediment of Madeira Archipelago, Portugal, and characterized using a polyphasic approach. This strain produced dark brown soluble pigments, bronwish black substrate mycelia and an aerial mycelium with yellowish white spores, when grown on GYM 50SW agar. The main respiratory quinones were MK-10(H4), MK-10(H6) and MK-10(H8). Diphosphatidylglycerol, phosphatidylethanolamine, three unidentified phospholipids and two glycophospholipids were identified as the main phospholipids. The major cellular fatty acids were iso-C16 : 1, iso-C16 : 0, anteiso-C17 : 1 and anteiso-C17 : 0. Phylogenetic analyses based on 16S rRNA gene showed that strain MA3_2.13T is a member of the genus Streptomyces and was most closely related to Streptomyces triticirhizae NEAU-YY642T (NR_180032.1; 16S rRNA gene similarity 97.9 %), Streptomyces sedi YIM 65188T (NR_044582.1; 16S rRNA gene similarity 97.4 %), Streptomyces mimosae 3MP-10T (NR_170412.1; 16S rRNA gene similarity 97.3 %) and Streptomyces zhaozhouensis NEAU-LZS-5T (NR_133874.1; 16S rRNA gene similarity 97.0 %). Genome pairwise comparisons with closest related type strains retrieved values below the threshold for species delineation suggesting that strain MA3_2.13T represents a new branch within the genus Streptomyces. Based on these results, strain MA3_2.13T (=DSM 115980T=LMG 33094T) is proposed as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces profundus sp. nov. is proposed.

Streptomyces akebiae sp. nov., a novel actinomycete isolated from rhizosphere soil of Akebia trifoliate

A novel actinomycete strain, designated as MG28^T, was isolated from rhizosphere soil of Akebia trifoliate. The taxonomic position of the strain was investigated by using a polyphasic approach. BLAST search of the full-length 16S rRNA gene sequence of strain MG28^T indicated it represented a member of the genus Streptomyces, and displayed 99.03%, 98.90%, 98.90%, 98.89%, 98.83% and less than 98.70% sequence similarities with S. phaeolivaceus GY16^T, S. deccanensis KCTC 19241^T, S. europaeiscabiei KACC 20186^T, S. fructofermentans CGMCC 4.1593^T, S. scabiei NRRL B-16523^T and other species of the genus Streptomyces with validly published names, respectively. Phylogenomic analysis indicated that strain MG28^T was closely related to Streptomyces deccanensis KCTC 19241^T. However, the average nucleotide identity values and the digital DNA-DNA hybridization values between them indicated that strain MG28^T represented a distinct species. Furthermore, strain MG28^T was also distinctly differentiated from strain KCTC 19241^T by morphological, physiological and biochemical characteristics. Therefore, strain MG28^T (= MCCC 1K06895^T = JCM 34922^T) represents a novel species of the genus Streptomyces, for which the name Streptomyces akebiae sp. nov. is proposed.

Streptomyces barringtoniae sp. nov., isolated from rhizosphere of plant with antioxidative potential

A novel actinomycete strain, JA03T, belonging to the genus Streptomyces , was isolated from the rhizosphere of Barringtonia racemosa (L.) Spreng. It was characterized taxonomically using a polyphasic approach. It grew at 25–37 °C, at pH 5–10 and with 6 % (w/v) NaCl. It contained ll-diaminopimelic acid in the cell-wall peptidoglycan. Ribose and glucose were detected in its whole-cell hydrolysate. The predominant cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0, C16 : 0, iso-C14 : 0 and iso-C15 : 0. Detected polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, unidentified phospholipids and unidentified amino lipids. Based on the results of 16S rRNA gene sequence analyses, strain JA03T showed highest similarity to Streptomyces filipinensis NBRC 12860T (98.76 %), Streptomyces fodineus TW1S1T (98.69 %) and Streptomyces shenzhennensis 172115T (98.68 %). Strain JA03T has a genome size of 9 092 851 bp with DNA G+C content of 71.28 mol%. The average nucleotide identity (ANI)-blast and ANI-MUMmer values of strain JA03T and related type strains were 79.6–89.2 and 86.7–92.5 %, respectively, and the digital DNA–DNA hybridization values were 27.3–46.4 %. Ethyl acetate extract of JA03T exhibited total phenolic content (33.4±0.6 µg mg−1 gallic acid equivalent), ferric reducing power value (70.8±1.8 µg mg−1 ascorbic acid equivalent) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (IC50=67.0±21.1 µg ml−1). Intracellular reactive oxygen species and NO production in RAW264.7 macrophage cells induced by H2O2 and lipopolysaccharide were inhibited with IC50 of 67.40 and 16.95 µg ml−1, respectively. Based on the taxonomic results, it has been concluded that strain JA03T represents a novel species of the genus Streptomyces for which the name Streptomyces barringtoniae sp. nov., is proposed. The type strain is JA03T (=LMG 32415T=TISTR 2999T).

Streptomyces phaeolivaceus sp. nov. and Streptomyces broussonetiae sp. nov., isolated from the leaves and rhizosphere soil of Broussonetia papyrifera

Two novel actinobacteria, designated strains GY16^T and T44^T, were isolated from the leaves and rhizosphere soil of Broussonetia papyrifera, respectively. A polyphasic approach was used for determining their taxonomic position. Results of 16S rRNA gene sequence analysis indicated that strain GY16^T exhibited highest similarities to Streptomyces cinereoruber subsp. fructofermentans CGMCC 4.1593^T (98.82 %), Streptomyces deccanensis KCTC 19241^T (98.76 %), Streptomyces scabiei NRRL B-16523^T (98.69 %), Streptomyces europaeiscabiei KACC 20186^T (98.69 %) and Streptomyces rishiriensis NBRC 13407^T (98.69 %), and strain T44^T showed 99.2, 99.1, 99.1 and <98.7 % sequence similarities to Streptomyces filipinensis CGMCC 4.1452^T, Streptomyces achromogenes subsp. achromogenes DSM 40028^T, Streptomyces durhamensis DSM 40539^T and other Streptomyces species, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain GY16^T formed an independent subclade, which indicated that strain GY16^T should belong to a potential novel species; and strain T44^T was closely related to S. filipinensis CGMCC 4.1452^T, S. achromogenes subsp. achromogenes DSM 40028^T, S. durhamensis DSM 40539^T and S. yokosukanensis DSM 40224^T. However, the multilocus sequence analysis evolutionary distance, average nucleotide identity and DNA-DNA hybridization values between closely related relatives were far from the species-level thresholds. In addition, phenotypic and chemotaxonomic characteristics further confirmed that strains GY16^T and T44^T belonged to two distinct species. Based on these results, it is concluded that the isolated strains represent novel species within the genus Streptomyces, for which the names Streptomyces phaeolivaceus sp. nov. (type strain GY16^T=CICC 24807^T=KCTC 49326^T) and Streptomyces broussonetiae sp. nov. (type strain T44^T=CICC 24819^T=JCM 33918^T) are proposed.

Streptomyces boncukensis sp. nov., isolated from saltern soil

A novel Gram-stain positive, aerobic, non-motile Actinobacterium, designated strain SB3404^T, was isolated from saltern soil collected from Boncuk Saltern, Sungurlu-Çorum, Turkey, and subjected to a polyphasic taxonomic approach. The organism has shown to have phylogenetic, chemotaxonomic, cultural and morphological properties consistent with its classification in the genus Streptomyces. 16S rRNA gene sequence analysis of strain SB3404^T showed that it is closely related to Streptomyces albus NBRC 13014^T (97.2% sequence similarity), Streptomyces xishensis YIM M 10378^T (96.7%) and Streptomyces abyssalis YIM M 10400^T (96.5%). The cell wall of the strain contained LL-diaminopimelic acid and the cell-wall sugars were glucose, mannose and ribose. The predominant menaquinones were identified as MK-9(H₈) and MK-9(H₆). The major cellular fatty acids were found to be iso-C_16:0, anteiso-C_17:0 and anteiso-C_15:0. Consequently, strain SB3404^T is considered to represent a novel species in the genus Streptomyces, for which the name Streptomyces boncukensis sp. nov. is proposed. The type strain is SB3404^T (= KCTC 49371^T = JCM 34018^T).