Klenkia sesuvii sp. nov., isolated from leaves of halophyte Sesuvium portulacastrum.

During a study on the diversity of culturable actinobacteria from coastal halophytes in Thailand, strain LSe6-5T was isolated from leaves of sea purslane (Sesuvium portulacastrum L.), and a polyphasic approach was employed to determine its taxonomic position. The 16S rRNA gene sequences analysis indicated that the strain was most closely related to Klenkia brasiliensis Tu 6233T (99.2 %), Klenkia marina YIM M13156T (99.1 %), and Klenkia terrae PB261T (98.7 %). The genome of strain LSe6-5T was estimated to be 4.33 Mbp in size, with DNA G+C contents of 74.3%. A phylogenomic tree based on whole-genome sequences revealed that strain LSe6-5T formed a clade with Klenkia marina DSM 45722T, indicating their close relationship. However, the average nucleotide identity (ANI)-blast, ANI-MUMmer, and dDDH values between strain LSe6-5T with K. marina DSM 45722T (87.1, 88.9, and 33.0 %) were below the thresholds of 95-96 % ANI and 70 % dDDH for identifying a novel species. Furthermore, strain LSe6-5T showed morphological and chemotaxonomic characteristics of the genus Klenkia. Cells were motile, rod-shaped, and Gram-stain-positive. Optimal growth of strain LSe6-5T occurred at 28 °C, pH 7.0, and 0-3 % NaCl. The whole-cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid, with galactose, glucose, mannose, and ribose as whole-cell sugars. The predominant menaquinones were MK-9(H4) and MK-9(H0). The polar lipid profile was composed of diphosphatidylglycerol, hydroxyphosphatidylethanolamine, phosphatidylinositol, glycophosphatidylinositol, an unidentified phospholipid, and an unidentified lipid. Major cellular fatty acids were iso-C15 : 0, iso-C16 : 0, and iso-C17 : 0. From the distinct phylogenetic position and combination of genotypic and phenotypic characteristics, it is supported that strain LSe6-5T represents a novel species of the genus Klenkia, for which the name Klenkia sesuvii sp. nov. is proposed. The type strain is strain LSe6-5T (=TBRC 16417T= NBRC 115929T).

Gordonia prachuapensis sp. nov. and Gordonia sesuvii sp. nov., two novel actinobacteria isolated from mangrove sediments and leaves of halophyte Sesuvium portulacastrum in Thailand.

A polyphasic approach was used to characterize two novel actinobacterial strains, designated PKS22-38T and LSe1-13T, which were isolated from mangrove soils and leaves of halophyte Sesuvium portulacastrum (L.), respectively. Phylogenetic analyses based on 16S rRNA gene sequences showed that they belonged to the genus Gordonia and were most closely related to three validly published species with similarities ranging from 98.6 to 98.1 %. The genomic DNA G+C contents of strains PKS22-38T and LSe1-13T were 67.3 and 67.2 mol%, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains were 93.3 and 54.9 %, respectively, revealing that they are independent species. Meanwhile, the ANI and dDDH values between the two novel strains and closely related type strains were below 80.5 and 24.0 %, respectively. Strains PKS22-38T and LSe1-13T contained C16 : 0, C18 : 1 ω9c and C18 : 0 10-methyl (TBSA) as the major fatty acids and diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylinositol as the main phospholipids. The predominant menaquinone was MK-9(H2). Based on phenotypic, chemotaxonomic, phylogenetic and genomic data, strains PKS22-38T and LSe1-13T are considered to represent two novel species within the genus Gordonia, for which the names Gordonia prachuapensis sp. nov. and Gordonia sesuvii sp. nov. are proposed, with strain PKS22-38T (=TBRC 17540T=NBRC 116256T) and strain LSe1-13T (=TBRC 17706T=NBRC 116396T) as the type strains, respectively.

Streptomyces pyxinae sp. nov. and Streptomyces pyxinicus sp. nov. isolated from lichen Pyxine cocoes (Sw.) Nyl.

Two novel actinobacteria, designated as LP05-1T and LP11T, were isolated from the lichen Pyxine cocoes (Sw.) Nyl. collected in Bangkok, Thailand. Genotypic and phenotypic analyses revealed that both strains represented members of the genus Streptomyces. The 16S rRNA gene of LP05-1T showed the highest similarity to the genome of Streptomyces gelaticus (98.41 %), while the 16S rRNA gene of LP11T was most similar to that of Streptomyces cinerochromogenes (98.93 %). The major menaquinones in LP05-1T were MK-9(H8), MK-9(H6), MK-9(H4) and MK-9(H2), and in LP11T, they were MK-9(H8) and MK-9(H6). Both strains exhibited the major fatty acids iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0, with LP05-1T also possessing iso-C17 : 0. The polar lipids of LP05-1T included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified lipid, while those of LP11T consisted of phosphatidylethanolamine, lyso-phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, an unidentified aminolipid and an unidentified glycolipid. The digital DNA-DNA hybridisation (dDDH) and average nucleotide identity (ANI) values indicated that both strains are distinct from each other with values below 70 and 95 %, respectively. dDDH, ANI by blast (ANIb) and ANI by MUMmer (ANIm) values between LP05-1T and its closely related type strains were 26.07-26.80 %, 81.24-82.01 % and 86.82-86.96 %, respectively, while those for LP11T and its closely related type strains were 30.70-31.70 %, 84.09-85.31 % and 88.02-88.39 %, respectively. The results of the taxonomic investigation, including dDDH and ANI values, indicate that LP05-1T and LP11T are novel type strains of two novel species within the genus Streptomyces. The names proposed are Streptomyces pyxinae sp. nov. for strain LP05-1T (=TBRC 15494T, =NBRC 115434T) and Streptomyces pyxinicus sp. nov. for strain LP11T (=TBRC 15493T, =NBRC 115421T).

Actinoplanes pyxinae sp. nov., a new lichen-derived rare actinobacterium exhibiting antimicrobial and anticancer activity.

A novel lichen-derived actinobacterium, designated Pm04-4T, was isolated from Pyxine cocoes (Sw.) Nyl. lichen collected from Chaiyaphum, Thailand. A polyphasic approach was used to describe the taxonomic position of the strain. The strain had morphological and chemotaxonomic properties similar to members of the genus Actinoplanes. It produced sporangia on the substrate mycelia. Meso-diaminopimelic acid, galactose, glucose and mannose were detected in the whole-cell hydrolysate of the strain. The major menaquinone was MK-9(H4). The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The predominant cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. Strain Pm04-4T showed the highest 16S rRNA gene sequence similarity to Actinoplanes akusuensis TRM 8003T (99.0 %). In the phylogenomic tree, strain Pm04-4T was positioned close to A. aksuensis TRM88003T, A. maris M416T, A. polyasparticus TRM66264T, A. hotanensis TRM88002T, A. abujensis DSM 45518T, A. bogorensis NBRC 110975T, A. brasiliensis DSM 43805T, A. lichenicola LDG1-01T and A. ovalisporus LDG1-06T. The average nucleotide identity and digital DNA-DNA hybridization values between strain Pm04-4T and its closely related neighbours were below the threshold values for describing new species. Moreover, the strain could be distinguished from its closely related type strains by phenotypic properties. Based on genotypic and phenotypic evidence, it can be concluded that strain Pm04-4T is a representative of a new Actinoplanes species for which the name Actinoplanes pyxinae sp. nov. is proposed. The type strain is Pm04-4T (=TBRC 16207T=NBRC 115836T). The type strain exhibited activity against Staphylococcus aureus ATCC 25923 as well as four yeast strains, namely Candida albicans TISTR 5554, Candida glabrata TISTR 5006, Candida krusei TISTR 5351 and Candida parapsilosis TISTR 5007. It also showed cytotoxicity against Caco-2, MNT-1 and MCF-7 cancer cells.

Saccharopolyspora ipomoeae sp. nov., an Actinomycete Isolated from Sweet Potato Field Soils.

During the course of the isolation of actinobacteria from sweet potato field soils collected from Phra Nakhon Si Ayutthaya province of Thailand, strain TS4A08T was isolated and subjected to a polyphasic taxonomic approach. The 16S rRNA gene sequence analysis of strain TS4A08T revealed that it is closely related to the type strains of Saccharopolyspora aridisoli, and Saccharopolyspora endophytica with 98.7%, and 98.6% similarity, respectively. However, phylogenetic analyses using 16S rRNA gene and genome sequences indicated that strain TS4A08T clustered with Saccharopolyspora flava AS4.1520T (98.2% similarity), well-supported by bootstrap values, and formed distinct line from the two closest strains. The average nucleotide identity (ANI) values and digital DNA-DNA hybridization (dDDH) values between the genome sequences of strain TS4A08T and the closest type strains of S. aridisoli, S. endophytica, and S. flava, were 86.1-93.2% and 33.1-49.6%, respectively, which were less than the threshold for the species delineation. The genome size and the DNA G + C content of strain TS4A08T were 6.6 Mbp and 70.5%, respectively. The strain grew well at 25-37 °C, pH range of 7-9, and NaCl concentration of 0-5% (w/v). Whole-cell hydrolysates contained meso-diaminopimelic acid. The major fatty acids were iso-C16:0, anteiso-C17:0, and iso-C15:0. Strain TS4A08T exhibited phosphatidylcholine in its polar lipid profile, with MK-9(H4) being the predominant isoprenologue. The strain exhibits typical chemotaxonomic properties of the genus Saccharopolyspora, including arabinose, galactose, and ribose as whole-cell sugars. Strain TS4A08T represents a novel species within the genus Saccharopolyspora, for which the name Saccharopolyspora ipomoeae sp. nov. is proposed. The type strain is TS4A08T (= TBRC 17271T = NBRC 115967T).

Streptomyces mahasarakhamensis sp. nov., an Endophytic Actinobacterium Isolated from Jasmine Rice and its Potential as plant Growth Promoter.

Two endophytic actinobacteria, strains MK5T and MK7, were isolated from the surface-sterilized root of Jasmine rice (Oryza sativa KDML 105). These strains were aerobic actinobacteria with a well-developed substrate and aerial mycelia that formed spiral spore chains. The type strains that shared the high 16S rRNA gene sequence similarity with both strains were Streptomyces naganishii NBRC 12892T (99.4%), "Streptomyces griseicoloratus" TRM S81-3T (99.2%), and Streptomyces spiralis NBRC 14215T (98.9%). Strains MK5T and MK7 are the same species sharing a digital DNA-DNA hybridization (dDDH) value of 95.3% and a 16S rRNA gene sequence similarity of 100%. Chemotaxonomic data confirmed the affiliation of strains MK5T and MK7 to the genus Streptomyces. Strains MK5T and MK7 contained MK-9(H4) as a major menaquinone; the whole-cell sugar of both strains was galactose and glucose. The strain MK5T shared 93.4% average nucleotide identity (ANI)-Blast, 95.5% ANI-MUMmer, 93% average amino acid identity, and 61.3% dDDH with S. spiralis NBRC 14215T. The polyphasic approach confirmed that strain MK5T represents a novel species, and the name Streptomyces mahasarakhamensis sp. nov. is proposed. The type strain is MK5T (= TBRC 17754 = NRRL B-65683). Genome mining, using an in silico approach and searching biosynthesis gene clusters of strains MK5T and MK7, revealed that the genomes contained genes encoding proteins relating to plant growth promotion, bioactive compounds, and beneficial enzymes. Strains MK5T and MK7 could produce indole acetic acid and solubilize phosphate in vitro.

Micromonospora thermarum sp. nov., an actinobacterium isolated from hot spring soil.

An actinomycete, designated strain HSS6-12T, was isolated from hot spring sediment collected from Ranong province, Thailand. The strain showed taxonomic characteristics consistent with those of members of the genus Micromonospora. HSS6-12T produced a single spore directly on the substrate mycelium, and no aerial mycelium was detected. The isomer of diamino acid presented in cell wall peptidoglycan was meso-diaminopimelic acid. Arabinose, xylose, glucose, and ribose were detected in whole-cell hydrolysates. MK-10(H4), MK-9(H4), and MK-10(H6) were major menaquinones. Major cellular fatty acids were iso-C16:0, iso-C15:0, and iso-C17:0. Phospholipid profile was composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, and phosphatidylinositolmannosides. 16S rRNA gene analysis revealed that HSS6-12T shared the highest 16S rRNA gene sequence similarity with Micromonospora inositola DSM 43819T (99.3%). In contrast, the genome analysis showed that HSS6-12T formed a tight taxonomic position in a phylogenomic tree with Micromonospora endolithica DSM 44398T. Moreover, the average nucleotide identity-blast, the digital DNA-DNA hybridization, and the average amino acid identity values between HSS6-12T and M. inositola DSM 43819T and M. endolithica DSM 44398T were 83.1-84.0%, 27.5-28.7%, and 80.4-82.2%, respectively, indicating that HSS6-12T was different species with both closely related Micromonospora-type strains. In addition, HSS6-12T could be discriminated from its closely related type strains by many physiological and biochemical characteristics. Thus, HSS6-12T could be considered a novel species of the genus Micromonospora, and the name Micromonospora thermarum is proposed for the strain. The type strain is HSS6-12T (= BCC 41915T = JCM 17127T).

Streptomyces telluris sp. nov., a promising terrestrial actinobacterium with antioxidative potentials.

An actinomycete strain, AA8T, which produced a long straight chain of spores (verticillati type), was isolated from the rhizosphere soil of Mangifera indica in Bangkok, Thailand. A polyphasic taxonomic study was carried out to establish the taxonomic position of the strain. Strain AA8T formed a tight taxonomic position in the 16S rRNA gene tree with Streptomyces roseifaciens MBT76T. In contrast, the genome-based taxonomic analysis showed that strain AA8T shared low average nucleotide identity-BLAST (94.1%), the digital DNA-DNA hybridization (58.2%), and the average amino acid identity (93.6%) values with S. roseifaciens MBT76T. Moreover, a combination of physiological and biochemical properties indicated that strain AA8T was distinguished from all Streptomyces species with effectively published names. Strain AA8T, therefore, represents a novel species of Streptomyces, and the name Streptomyces telluris is proposed for the strain. The type strain is AA8T (= TBRC 8483T = NBRC 113461T). The chemical investigation led to the isolation of nine known compounds (compounds 1-9). Among these compounds, compound 7 (3,4-dihydroxybenzaldehyde) possesses strong antioxidant activity equal to ascorbic acid, a powerful antioxidative agent.

Streptomyces phytophilus sp. nov., an endophytic actinobacterium with biosynthesis potential as an antibiotic producer.

An endophytic actinobacterium, strain PIP175T, was isolated from the root sample of a native apricot tree (Pittosporum angustifolium) growing on the Bedford Park campus of Flinders University, Adelaide, South Australia. This strain is a Gram stain-positive, aerobic actinobacterium with well-developed substrate mycelia. Aerial mycelia rarely produce spores and the spore chain is spiral. Strain PIP175T showed the highest 16S rRNA gene sequence similarity to Streptomyces aculeolatus DSM 41644T (99.4 %). Other closely related phylogenetic representatives include Streptomyces synnematoformans DSM 41902T (98.3 %), Streptomyces albospinus NBRC 13846T (97.6 %), Streptomyces cacaoi subsp. cacaoi NRRL B-1220T (97.5 %) and Streptomyces ruber NBRC 14600T (97.4 %). The major cellular fatty acid of this strain was iso-C16 : 0 and the major menaquinone was MK-9(H6). The whole-cell sugar contained galactose, glucose and mannose. Chemotaxonomic data confirmed that strain PIP175T belonged to the genus Streptomyces. Digital DNA-DNA hybridization, average nucleotide identity based on blast and OrthoANIu results between strain PIP175T and S. aculeolatus DSM 41644T were 60.0, 94.1 and 94.9 %, respectively. Genotypic and phenotypic data and genome analysis results allowed the differentiation of strain PIP175T from its closest species with validly published names. Strain PIP175T showed good activity against methicillin-resistant Staphylococcus aureus 03120385. Genome mining of strain PIP175T revealed biosynthetic genes encoding proteins relating to antibiotic production, plant growth promotion and biodegradation enzymes. The name proposed for the new species is Streptomyces phytophilus sp. nov. The type strain is PIP175T (=DSM 103379T=TBRC 6026T).

Nocardiopsis suaedae sp. nov. and Nocardiopsis endophytica sp. nov., two novel halophilic actinobacteria isolated from halophytes.

A polyphasic approach was used to describe two halophilic actinobacterial strains, designated LSu2-4T and RSe5-2T, which were isolated from halophytes [Suaeda maritima (L.) Dum. and Sesuvium portulacastrum (L.) L.] collected from Prachuap Khiri Khan province, Thailand. Comparative analysis of 16S rRNA gene sequences showed that strains LSu2-4T and RSe5-2T were assigned to the genus Nocardiopsis, with Nocardiopsis chromatogenes YIM 90109T(99.2 and 99.2 % similarities, respectively) and Nocardiopsis halophila DSM 44494T(99.0 and 98.8 % similarities, respectively) being their closely related strains. Whereas the 16S rRNA gene sequence similarity between LSu2-4T and RSe5-2T was 99.4 %. Phylogenetic and phylogenomic analyses based on 16S rRNA gene and whole-genome sequences revealed that both strains clustered with N. chromatogenes YIM 90109T and N. halophila DSM 44494T. The average nucleotide identity (ANI) based on blast, ANI based on MUMmer and digital DNA-DNA hybridization (dDDH) relatedness values between the two strains and their closest type strains were below the threshold values for identifying a novel species. Morphological characteristics and chemotaxonomic features of both strains were typical for the genus Nocardiopsis by formed well-developed substrate mycelia and aerial mycelia which fragmented into rod-shaped spores. Whole-cell hydrolysates contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were variously hydrogenated with 10 isoprene units and contained phosphatidylcholine in their polar lipid profiles. Major fatty acids were iso-C16:0 and 10-methyl C18:0. In silico analysis predicted that the genomes of LSu2-4T and RSe5-2T contained genes associated with stress responses and biosynthetic gene clusters encoding diverse bioactive metabolites. Characterization based on chemotaxonomic, phenotypic, genotypic and phylogenetic evidence demonstrated that strains LSu2-4T and RSe5-2T represents two novel species of the genus Nocardiopsis, for which the names Nocardiopsis suaedae sp. nov. (type strain LSu2-4T=TBRC 16415T=NBRC 115855T) and Nocardiopsis endophytica sp. nov. (type strain RSe5-2T=TBRC 16416T=NBRC 115856T) are proposed.

Streptomyces silvisoli sp. nov., a polyene producer, and Streptomyces tropicalis sp. nov., two novel actinobacterial species from peat swamp forests in Thailand.

Two novel actinobacterial strains, designated RB6PN23T and K1PA1T, were isolated from peat swamp soil samples in Thailand and characterized using a polyphasic taxonomic approach. The strains were filamentous Gram-stain-positive bacteria containing ll-diaminopimelic acid in their whole-cell hydrolysates. Phylogenetic analysis of their 16S rRNA gene sequences revealed that strain RB6PN23T was most closely related to Streptomyces rubrisoli (99.1 % sequence similarity) and Streptomyces ferralitis (98.5%), while strain K1PA1T showed 98.8 and 98.7% sequence similarities to Streptomyces coacervatus and Streptomyces griseoruber, respectively. However, the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values were below the species-level thresholds (95-96 % ANI and 70 % dDDH). The genomes of strains RB6PN23T and K1PA1T were estimated to be 7.88 Mbp and 7.39 Mbp in size, respectively, with DNA G+C contents of 70.2 and 73.2 mol%. Moreover, strains RB6PN23T and K1PA1T encode 37 and 24 putative biosynthetic gene clusters, respectively, and in silico analysis revealed that these new species have a high potential to produce unique natural products. Genotypic and phenotypic characteristics confirmed that strains RB6PN23T and K1PA1T represented two novel species in the genus Streptomyces. The names proposed for these strains are Streptomyces silvisoli sp. nov. (type strain RB6PN23T=TBRC 17040T=NBRC 116113T) and Streptomyces tropicalis sp. nov. (type strain K1PA1T=TBRC 17041T=NBRC 116114T). Additionally, a giant linear polyene compound, neotetrafibricin A, exhibiting antifungal activity in strain RB6PN23T, was identified through HPLC and quadrupole time-of-flight MS analysis. The crude extract from the culture broth of strain RB6PN23T exhibited strong antifungal activity against Fusarium verticillioides, Fusarium fujikuroi and Bipolaris zeicola. This finding suggests that strain RB6PN23T could be a promising candidate for biological control of fungal diseases.

Streptomyces cylindrosporus sp. nov. and Streptomyces spinosisporus sp. nov.: two new endophytic actinobacteria isolated from the roots of Barleria lupulina Lindl.

Two endophytic actinobacteria, designated as strains 7R015T and 7R016T, were isolated from the roots of Barleria lupulina collected in Thailand. The morphological characteristics and results of chemotaxonomic studies and 16S rRNA gene analysis indicated that both strains represented members of the genus Streptomyces. They contained ll-diaminopimelic acid in the peptidoglycan. Ribose and glucose were detected as the whole-cell sugars. MK-9(H4), MK-9(H6) and MK-9(H8), were found as the membrane menaquinone. The predominant cellular fatty acids detected were iso-C16 : 0 and anteiso-C15 : 0. The genomes of both strains harboured biosynthetic gene clusters for melanin, terpene, lanthipeptide, polyketides, non-ribosomal peptide synthetase, siderophore and ectoine. The 16S rRNA gene sequence of 7R015T showed the highest similarity to that of Streptomyces pseudovenezuelae DSM 40212T (98.6 %), Streptomyces cyaneus NRRL B2296T (98.6 %) and Streptomyces curacoi DSM 40107T (98.6 %). Strain 7R016T showed the highest 16S rRNA gene sequence similarity to Streptomyces gilvifuscus NBRC 110904T (98.2 %), which is lower than the threshold value for 16S rRNA gene sequence similarity for differentiation at the species level (98.65 %). Comparative genome analysis revealed that the genomes of 7R015T, 7R016T and the closely related type strains had an average nucleotide identity (ANI) of less than 95 % and a digital DNA-DNA hybridisation (dDDH) of less than 70 %, the thresholds for species demarcation. On the basis of the results of the polyphasic study, strains 7R015T and 7R016T represent novel species of the genus Streptomyces and are named herein as Streptomyces cylindrosporus sp. nov. (=NBRC 115200T = TBRC 14542T) for strain 7R015T and Streptomyces spinosisporus sp. nov. (=NBRC 115201T = TBRC 14543T) for strain 7R016T.

Streptomyces salinarius sp. nov., an actinomycete isolated from solar saltern soil.

An actinobacterium, designated strain SS06011T, was isolated from solar saltern soil collected from Samut Sakhon province, Thailand. The taxonomic position of this strain was established using the polyphasic taxonomic approach. The strain produced grey aerial spore mass on International Streptomyces Project 2 seawater agar that differentiated into spiral spore chains with rugose-surfaced spores. Strain SS06011T was found to have ll-diaminopimelic acid in the cell peptidoglycan. Whole-cell hydrolysates contained galactose, glucose and ribose. MK-9(H6) and MK-9(H4) were major menaquinones. The major cellular fatty acids comprised iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylinositol were detected in cells. These characteristics were coincident with the typical morphological and chemotaxonomic properties of the genus Streptomyces. The taxonomic affiliation at the genus level of this strain could also be confirmed by its 16S rRNA gene sequence data. Strain SS06011T showed the highest 16S rRNA gene sequence similarity to Streptomyces ardesiacus NRRL B-1773T (99.1 %), Streptomyces coelicoflavus NBRC 15399T (99.1 %) and Streptomyces hyderabadensis OU-40T (99.1 %). Digital DNA-DNA hybridization (dDDH), average nucleotide identity-blast (ANIb) and average amino acid identity (AAI) values between strain SS06011T and its closely related type strains, S. ardesiacus NBRC 15402T, S. coelicoflavus NBRC 15399T and S. hyderabadensis JCM 17657T, were in the range of 45.4-48.4 % (for dDDH), 90.8-91.9 % (for ANIb) and 90.8-91.7 % (for AAI), respectively, which are lower than the cut-off criteria for species delineation. The DNA G+C content of genomic DNA was 71.9 mol%. With the differences in physiological, biochemical and genotypic data, strain SS06011T could be discriminated from its closest neighbours. Thus, strain SS06011T should be recognized as representing a novel species of the genus Streptomyces, for which the name Streptomyces salinarius sp. nov. is proposed. The type strain is SS06011T (=TBRC 9951T=NBRC 113998T).

Streptomyces macrolidinus sp. nov., a novel soil actinobacterium with potential anticancer and antimalarial activity.

A novel actinomycete, strain RY43-2T, belonging to the genus Streptomyces, was isolated from a peat swamp forest soil collected from Rayong Province, Thailand. The strain was characterized by using a polyphasic approach. The cell-wall peptidoglycan contained ll-diaminopimelic. Ribose and glucose were detected in its whole-cell hydrolysates. The strain contained anteiso-C15:0, iso-C14:0 and iso-C16:0 as the predominant fatty acids, and MK-9(H4), MK-9(H6) and MK-9(H8) as the major menaquinones. The phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, three unidentified ninhydrin-positive phospholipids and two unidentified phospholipids. Strain RY43-2T showed the highest 16S rRNA gene similarity to Streptomyces misionensis JCM 4497T (98.9 %) and Streptomyces lichenis LCR6-01T (98.9 %). The draft genome of RY43-2T was 6.7 Mb with 6078 coding sequences with an average G+C content of 70.8 mol%. Genomic analysis revealed that the average nucleotide identity (ANI) values based on blast (ANIb) and MUMmer (ANIm) between strain RY43-2T and S. misionensis JCM 4497T were 80.1 and 86.1%, respectively. The ANIb and ANIm values between strain RY43-2T and S. lichenis LCR6-01T were 77.0 and 85.5%, respectively. The digital DNA-DNA hybridization values were 25.2 and 23.0% in comparison with the draft genomes of S. misionensis JCM 4497T and S. lichenis LCR6-01T, respectively. The results of taxonomic analysis suggested that strain RY43-2T represented a novel species of the genus Streptomyces for which the name Streptomyces macrolidinus sp. nov. is proposed. The type strain is RY43-2T (=TBRC 7286T=NBRC 115640T). Strain RY43-2T exhibited antimicrobial activity against Enterococcus faecium ATCC 51559, Colletotrichum capsici BMGC 106 and Colletotrichum gloeosporioides BMGC 107 with the minimum inhibitory concentration values of 25.0, 12.5, and 6.25 µg ml-1. It also exhibited potent antimalarial activity against Plasmodium falciparum K1 with IC50 of 0.0031 µg ml-1. In addition, it showed cytotoxicity against Vero, KB, MCF-7 and NCI-H187 with IC50 values of 0.0347, 6.15, 3.36 and 0.0352 µg ml-1, respectively.

Gordonia aquimaris sp. nov., a novel marine actinobacterium isolated from seawater in the upper gulf of Thailand.

An actinobacterium strain, SW21T, was isolated from seawater collected in the upper Gulf of Thailand. Cells were Gram-stain-positive, aerobic and rod-shaped. Growth was observed from 15 to 37 °C and at pH 6-8. Maximum NaCl for growth was 14 % (w/v). meso-Diaminopimelic acid, arabinose, galactose, glucose, rhamnose and ribose were detected in the whole-cell hydrolysate. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside were detected as the phospholipids in the cells. The major menaquinones were MK-9(H2) and MK-7(H2). The major cellular fatty acids were C16 : 0, C18 : 1 ω9c, C18 : 0 and C18 : 010-methyl (TBSA). The 16S rRNA gene sequence data supported the assignment of strain SW21T to the genus Gordonia and showed that Gordonia mangrovi KCTC 49383T (98.7 %) was the closest relative. Moreover, the average nucleotide identity-blast (85.5 %) and digital DNA-DNA hybridization (30.7 %) values between strain SW21T and its closest neighbour were below the threshold values for delineation of a novel species. The combination of genotypic and phenotypic data indicated that strain SW21T is representative of novel species of the genus Gordonia. The name Gordonia aquimaris sp. nov. is proposed for strain SW21T. The type strain is SW21T (=TBRC 15691T=NBRC 115558T).

Streptomyces zingiberis sp. nov., an endophytic actinobacterium isolated from the root tissue of Zingiber montanum.

An endophytic actinobacterium, designated strain PLAI 1-29T, was isolated from the root tissue of Zingiber montanum collected from Pathum Thani province, Thailand. Strain PLAI 1-29T was characterized using a polyphasic taxonomic approach. It typically exhibited morphological and chemotaxonomic properties of the genus Streptomyces. Strain PLAI 1-29T produced a spiral spore chain on aerial mycelium and grew at 15-40 °C, pH 6-10 on International Streptomyces Project 2 agar. The maximum NaCl concentration for growth was 9 % (w/v). Cells of strain PLAI 1-29T presented ll-diaminopimelic acid, arabinose, galactose and ribose. The detected phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The major menaquinones were MK-9(H6) and MK-9(H8). The major cellular fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The genome-based taxonomic details revealed the assignment of strain PLAI 1-29T to the genus Streptomyces and exhibited low threshold values for the delineation of a novel species by average nucleotide identity-blast (84.0%), average amino acid identity (80.0%) and digital DNA-DNA hybridization (27.6%) with its closest type strain, Streptomyces xinghaiensis S187T. Furthermore, several differential physiological and biochemical characteristics were detected between strain PLAI 1-29T and the closest type strain. Based on the combined phenotypic and genomic features, strain PLAI 1-29T (=TBRC 7645T=NBRC 113170T) is considered to represent a new Streptomyces species, for which we propose the name Streptomyces zingiberis sp. nov.

Micromonospora solifontis sp. nov., an actinobacterium isolated from hot spring soil.

An actinobacterium strain, PPF5-17T, was isolated from hot spring soil collected from Chiang Rai province, Thailand. The strain exhibited morphological and chemotaxonomic properties similar to those of members of the genus Micromonospora. Colonies of PPF5-17T were strong pinkish red and turned black after sporulation in ISP 2 agar medium. Cells formed single spores directly on the substrate mycelium. Growth was observed from 15 to 45 °C and at pH 5-8. Maximum NaCl concentration for growth was 3 % (w/v). PPF5-17T was found to have meso-diaminopimelic acid, xylose, mannose and glucose in the whole-cell hydrolysate. Diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositolmannosides were observed as the membrane phospholipids. MK-10(H6), MK-9(H6), MK-10(H4) and MK-9(H4) were the major menaquinones. The predominant cellular fatty acids were iso-C15 : 0, iso-C17 : 0, anteiso-C17 : 0 and iso-C16 : 0. PPF5-17T shared the highest 16S rRNA gene sequence similarity with Micromonospora fluminis LMG 30467T (99.3 %). A genome-based taxonomic study revealed that PPF5-17T was closely related to Micromonospora aurantinigra DSM 44815T in the phylogenomic tree with an average nucleotide identity by blast (ANIb) of 87.7 % and a digital DNA-DNA hybridization (dDDH) value of, 36.1 % which were below the threshold values for delineation of a novel species. Moreover, PPF5-17T could be distinguished from its closest neighbours, M. fluminis LMG 30467T and M. aurantinigra DSM 44815T, with respect to a broad range of phenotypic properties. Thus, PPF5-17T represents a novel species, for which the name Micromonospora solifontis sp. nov. is proposed. The type strain is PPF5-17T (= TBRC 8478T = NBRC 113441T).

Paeniglutamicibacter quisquiliarum sp. nov., isolated from midden soil waste.

A Gram-stain-positive, irregular short-rod and non-motile bacterium, designated strain ABSL32-1T, was isolated from a soil sample collected from the Suphan Buri municipal solid waste disposal area. According to the results of a polyphasic taxonomic study, a novel species belonging to the genus Paeniglutamicibacter was described. Strain ABSL32-1T grew optimally at 20-25 °C and at pH 6.0-8.0 in the presence of 1 % (w/v) NaCl. The whole-cell sugars were ribose, mannose and glucose. The peptidoglycan structure contained A4α peptidoglycan (Lys-Glu; A11.54). The polar lipids contained digalactosyldiacylglycerol, diphosphatidylglycerol, phosphatidylglycerol, unidentified phospholipids and two unidentified lipids. The major menaquinones were MK-9 and MK-10. The major cellular fatty acid was anteiso-C15 : 0 (70.1 %). Based on 16S rRNA gene sequence analysis, strain ABSL32-1T showed the highest similarity to Paeniglutamicibacter sulfureus DSM 20167T (99.5 %), followed by Paeniglutamicibacter antarcticus SPC26T (99.0 %) and Paeniglutamicibacter psychrophenolicus AG31T (98.8 %). The genome of strain ABSL32-1T is 4.4 Mbp with a DNA G+C content of 66.0 mol%. The average nucleotide identity values between strain ABSL32-1T and the type strains P. sulfureus DSM20167T, P. antarcticus SPC26T and P. psychrophenolicus AG31T were 86.6, 74.7 and 83.6 %, respectively. On the basis of phenotypic, chemotaxonomic and genotypic properties, strain ABSL32-1T is proposed to represent a novel species to be named Paeniglutamicibacter quisquiliarum sp. nov. The type strain is ABSL32-1T (=TBRC 14976T=NBRC 115252T).

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).

Glycomyces amatae sp. nov., isolated from a yellow-ringed grass moth (Amata sperbius).

A novel mycelium-forming actinomycete strain, designated A-F 0318T, was isolated from a yellow-ringed grass moth (Amata sperbius) collected from Phitsanulok Province, Thailand. Long chains of non-motile cylindrical spores with a smooth surface developed on aerial mycelia. The polyphasic taxonomic study suggested that strain A-F 0318T belonged to the genus Glycomyces. The 16S rRNA gene sequence analysis indicated that strain A-F 0318T was closely related to Glycomyces harbinensis LL-DO5139T with 97.94 % sequence similarity. The average nucleotide identity (ANI) based on blast, ANI based on the MUMmer algorithm and average amino acid identity values of strain A-F 0318T with G. harbinensis LL-DO5139T were 86.9, 89.1 and 84.24 %, respectively. The digital DNA-DNA hybridization value between A-F 0318T and its closest relative, G. harbinensis LL-DO5139T was 33.8 %. The digital G+C content of the genomic DNA was 71.7 mol%. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose, xylose, glucose and galactose. The predominant menaquinone was MK-10(H4). The predominant fatty acids were iso-C16 : 0, anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 1 G. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, two unknown phosphoglycolipids and one unknown phospholipid. Based on comparative analysis of genotypic, phenotypic and chemotaxonomic data, the novel actinomycete strain A-F 0318T (=TBRC 13612T=NBRC 115417T) represents the type strain of a novel species, for which the name Glycomyces amatae sp. nov. is proposed.