Actinomycetospora aeridis sp. nov., Actinomycetospora flava sp. nov. and Actinomycetospora aurantiaca sp. nov., endophytic actinobacteria isolated from wild orchid (Aerides multiflora Roxb).

Three novel mycelium-forming actinobacteria, designated OC33-EN06T, OC33-EN07T, and OC33-EN08T, were isolated from wild orchid (Aerides multiflora Roxb), collected from a hill evergreen forest in Northern Thailand. Strains OC33-EN06T and OC33-EN07T showed the highest 16S rRNA gene similarity with Actinomycetospora lutea TT00-04T, 99.17 and 99.45%, respectively. Strain OC33-EN08T showed high similarity with four species, namely 'Actinomycetospora termitidis Odt1-22T' (99.37%), Actinomycetospora chiangmaiensis DSM 45062T (99.02%), Actinomycetospora corticicola 014-5T (99.02%), and Actinomycetospora soli SF1T (98.81%). Comparative genome analysis of OC33-EN06T, OC33-EN07T, and OC33-EN08T with the closely related type strains showed that average nucleotide identity (ANI) based on blast, ANI based on MUMmer, and average amino acid identity values were less than 95% and the digital DNA-DNA hybridization values were less than 70%, all below the thresholds for species demarcation. The digital G+C content of OC33-EN06T, OC33-EN07T, and OC33-EN08T were 74.5, 74, and 74 mol%, respectively. These three strains developed bud-like chains of non-motile cylindrical spores with a smooth surface. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose, arabinose, and galactose. The predominant menaquinone was MK-8(H4). The phospholipid profile included phosphatidylcholine, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and phosphatidylinositol. Based on comparative analysis of genotypic, phenotypic and chemotaxonomic data, strains OC33-EN06T (=TBRC 18349T=NBRC 116543T), OC33-EN07T (=TBRC 18350T=NBRC 116544T), and OC33-EN08T (=TBRC 18318T=NBRC 116542T) represent the type strains of three novel species of the genus Actinomycetospora for which the names Actinomycetospora aeridis sp. nov., Actinomycetospora flava sp. nov., and Actinomycetospora aurantiaca sp. nov., are proposed.

Fungal communities as dual indicators of river biodiversity and water quality assessment.

Given their ecological importance, bioindicators are used for the assessment of the health of river ecosystems. This study explored the fungal compositions and the potential of fungal taxa as bioindicators for indicating the water quality of the Mekong River, as the use of fungal indicators of the Mekong River was not previously well characterized. The Mekong River exhibited dynamic variations in both physicochemical/hydrochemical properties and fungal communities according to seasons and locations. The results revealed the dominance of alkaline earth metal ions and weak acids in the water. The magnesium-bicarbonate water type was found in the dry season, but the water became the chloride-calcium type or mixed type of magnesium-bicarbonate and chloride-calcium in the rainy season at downstream sites. Fungal composition analysis revealed the dominance of Chytridiomycota in the dry season and intermediate periods, and Ascomycota and Basidiomycota in the rainy season. The fungal communities were influenced by stochastic and deterministic assembly processes, mainly homogeneous selection, heterogeneous selection, and dispersal limitation. The extent of environmental filtering implied that some fungal taxa were affected by environmental conditions, suggesting the possibility of identifying certain fungal taxa suitable for being bioindicators of water quality. Subsequently, machine learning with recursive feature elimination identified specific fungal bins mostly consisting of Agaricomycetes (mainly Polyporales, Agaricales, and Auriculariales), Dothideomycetes (mainly Pleosporales), Saccharomycetes (mainly Saccharomycetales), Chytridiomycota, and Rozellomycota as bioindicators that could predict ambient and irrigation water quality with high selectivity and sensitivity. These results thus promote the use of fungal indicators to assess the health of the river.

Elucidating potential bioindicators from insights in the diversity and assembly processes of prokaryotic and eukaryotic communities in the Mekong River.

Drivers for spatio-temporal distribution patterns of overall planktonic prokaryotes and eukaryotes in riverine ecosystems are generally not fully understood. This study employed amplicon metabarcoding to investigate the distributions and assembly mechanisms of bacterial and eukaryotic communities in the Mekong River. The prevailing bacteria taxa were found to be Betaproteobacteria, Actinobacteria, and Bacteroidetes, while the dominant eukaryotic organisms were cryptophytes, chlorophytes, and diatoms. The community assemblages were influenced by a combination of stochastic and deterministic processes. Drift (DR) and dispersal limitation (DL), signifying the stochastic mechanism, were the main processes shaping the overall prokaryotic and eukaryotic communities. However, homogeneous selection (HoS), indicating deterministic mechanism, played a major role in the assembly process of core prokaryotic communities, especially in the wet season. In contrast, the core eukaryotic communities including Opisthokonta, Sar, and Chlorophyta were dominated by stochastic processes. The significance of HoS within prokaryotic communities was also found to exhibit a decreasing trend from the upstream sampling sites (Chiang Saen and Chiang Khan, Nong Khai) towards the downstream sites (Mukdahan, and Khong Chiam) of the Mekong River. The environmental gradients resulting from the site-specific variations and the gradual decrease in elevation along the river may have a potential influence on the role of HoS in community assembly. Crucial environmental factors that shape the phylogenetic structure within distinct bins of the core prokaryotic communities including water depth, temperature, chloride, sodium, and sulphate were identified, as inferred by their correlation with the beta Net Relatedness Index (betaNRI) during the wet season. Overall, these findings enhance understanding of the complex mechanisms governing the spatio-temporal dynamics of prokaryotic and eukaryotic communities in the Mekong River. Finally, insights gained from this study could provide information on further use of specific core bacteria as microbial-based bioindicators that are effective for the assessment and conservation of the Mekong River ecosystem.

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.

Prauserella cavernicola sp. nov., isolated from cave rock.

A novel actinomycete, designated strain ASG 168T, was isolated from cave rock collected from Stegodon Sea Cave in Thailand. Long chains of non-motile spores that were oval or spherical in shape with a smooth surface developed on aerial mycelia. Substrate mycelia fragmented into irregular rod-shaped elements. A polyphasic taxonomic study showed that strain ASG 168T had typical characteristics of members of the genus Prauserella. 16S rRNA gene sequence analysis indicated that strain ASG 168T shared 97.5 % similarity with Prauserella marina MS498T and 96.7 % with Prauserella coralliicola SCSIO 11529T. Average nucleotide identity values with P. coralliicola SCSIO 11529T and P. marina MS498T were 82.98 and 76.08 %, respectively. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose, arabinose and galactose. The predominant menaquinone was MK-9(H4). The predominant fatty acids were iso-C16 : 0, C16 : 0 and summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c). The phospholipid profile consisted of phosphatidylethanolamine, phosphatidylmethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and two unknown phospholipids. The G+C content of the genomic DNA was 70.6 mol%. Differentiation of strain ASG 168T from closely related species was evident from digital DNA-DNA hybridization values of 29.2 and 21.3 % with P. coralliicola and P. marina, respectively. Based on comparative analysis of phenotypic, chemotaxonomic and genotypic data, the novel actinomycete strain ASG 168T (=TBRC 13679T=NBRC 114887T) is proposed to be the type strain of a novel species, Prauserella cavernicola sp. nov.

Uncovering multi-faceted taxonomic and functional diversity of soil bacteriomes in tropical Southeast Asian countries.

Environmental microbiomes encompass massive biodiversity and genetic information with a wide-ranging potential for industrial and agricultural applications. Knowledge of the relationship between microbiomes and environmental factors is crucial for translating that information into practical uses. In this study, the integrated data of Southeast Asian soil bacteriomes were used as models to assess the variation in taxonomic and functional diversity of bacterial communities. Our results demonstrated that there were differences in soil bacteriomes across different geographic locality with different soil characteristics: soil class and pH level. Such differences were observed in taxonomic diversity, interspecific association patterns, and functional diversity of soil bacteriomes. The bacterial-mediated biogeochemical cycles of nitrogen, sulfur, carbon, and phosphorus illustrated the functional relationship of soil bacteriome and soil characteristics, as well as an influence from bacterial interspecific interaction. The insights from this study reveal the importance of microbiome data integration for future microbiome research.

Cryptosporangium phraense sp. nov., isolated from plant litter.

A novel zoosporic actinomycete, designated strain A-T 5661T, was isolated from plant litter collected in Thailand. Strain A-T 5661T developed large multilocular sporangia containing motile sporangiospores at the ends of sporangiophores on substrate mycelium. The results of our polyphasic taxonomic study demonstrated that the strain had characteristics typical of members of the genus Cryptosporangium. The 16S rRNA gene sequence and phylogenetic analyses indicated that strain A-T 5661T shared the sequence similarity ≤98.5 % with all members of the genus Cryptosporangium. The values of DNA-DNA relatedness that distinguished this novel strain from its closest related species were below 70 %. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars were acofriose, arabinose, galactose, glucose, mannose, xylose and ribose. The predominant menaquinones were MK-9(H8) and MK-9(H6) with minor amounts of MK-9(H4) and MK-9(H2). The predominant fatty acids were iso-C16 : 0, C18 : 1ω9c and anteiso-C17 : 0. The polar lipid profile consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and unidentified polar lipids. The G+C content of the genomic DNA was 71.6 mol%. Based on comparative analysis of phenotypic, chemotaxonomic and genotypic data, the novel zoosporic actinomycete A-T 5661T (=TBRC 8127T=NBRC 113237T) is proposed to be the type strain of a novel species, Cryptosporangium phraense sp. nov.

Gordonia asplenii sp. nov., isolated from humic soil on bird's nest fern (Asplenium nidus L.).

A novel member of the actinobacteria, designated strain A-T 0013T, was isolated from humic soil on a bird's nest fern (Asplenium nidus L.) collected from Khao Yai National Park in Thailand. According the results of a polyphasic taxonomic study, A-T 0013T had characteristics typical of members of the genus Gordonia. The 16S rRNA gene sequence indicated that A-T 0013T shared ≤98 % sequence similarity with all members of the genus Gordonia. The most closely related species was Gordonia effusa IFM 10200T (97.92 % sequence similarity). The average nucleotide identity based on blast (ANIb) value with G. effusa IFM 10200T was 76.81 %. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose, arabinose and galactose. The predominant menaquinone was MK-9(H2). The predominant fatty acids were C16 : 0, C18 : 1ω9c, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), and C18 : 0 10-methyl. Mycolic acid was present. The polar lipid profile for this strain ncluded diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The G+C content of the genomic DNA was 66.1 mol%. Differentiation of A-T 0013T from the most closely related species, Gordonia effusa IFM 10200T, was evident from digital DNA-DNA hybridization values of 21.8 %. On the basis of the results of comparative analysis of phenotypic, chemotaxonomic and genotypic data, strain A-T 0013T is concluded to represent a novel species of the genus Gordonia, for which the name Gordonia asplenii sp. nov. is proposed. The type strain is A-T 0013T (=TBRC 11910T=NBRC 114549T).

Verrucosispora endophytica sp. nov., isolated from the root of wild orchid (Grosourdya appendiculata (Blume) Rchb.f.).

A novel endophytic filamentous bacterium strain A-T 7972T, was isolated from wild orchid Grosourdya appendiculata (Blume) Rchb.f. collected in Thailand. The bacterium developed single non-motile spores with warty surface on substrate mycelia. The taxonomic position was described using a polyphasic approach. The 16S rRNA gene sequence and phylogenetic analysis indicated that strain A-T 7972T belonged to the genus Verrucosispora and shared the highest sequence similarity with V. lutea YIM 013T (98.71 %) and V. gifhornensis DSM 44337T (98.53 %). The values of DNA-DNA relatedness that distinguished this novel strain from its closest species were below 70 %. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars were mannose, ribose, glucose and xylose. The predominant menaquinone was MK-9(H4). The predominant fatty acids were branched fatty acids iso-C15 : 0 and iso-C16 : 0. The diagnostic phospholipids profile consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. The G+C content of the genomic DNA was 70.5 mol%. Based on its phenotypic, chemotaxonomic and genotypic characteristics, the new isolate A-T 7972T (=BCC 50981T=TBRC 6031T=NBRC 112512T) is proposed to be the type strain of novel species, Verrucosispora endophytica sp. nov.

Actinoplanes subglobosus sp. nov., isolated from mixed deciduous forest soil.

A novel filamentous bacterial strain, A-T 5400T, which developed subglobose sporangia at the end of sporangiophores on substrate mycelia, was isolated from mixed deciduous forest soil collected in Thailand. The taxonomic position of this micro-organism was described using a polyphasic approach. The 16S rRNA gene sequence and phylogenetic analysis indicated that strain A-T 5400T belonged to the genus Actinoplanes and was most closely related to 'Actinoplanes hulinensis' NEAU-M9 (98.82 % 16S rRNA gene sequence similarity) and Actinoplanes philippinensis NBRC 13878T (98.75 %). The DNA-DNA relatedness values that distinguished the novel strain from the closest species were below 70 %. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars were ribose, galactose, glucose and xylose. The predominant menaquinone was MK-9(H4). The diagnostic phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The predominant cellular fatty acids were unsaturated fatty acids C16 : 1, branched fatty acids iso-C16 : 0 and iso-C15 : 0. The G+C content of the genomic DNA was 71 mol%. Following evidence from phenotypic, chemotaxonomic and genotypic studies, the new isolate is proposed to represent a novel species of the genus Actinoplanes named Actinoplanes subglobosus sp. nov. The type strain is A-T 5400T (=BCC 42734T=TBRC 5832T=NBRC 109645T).

Planomonospora corallina sp. nov., isolated from soil.

A novel actinomycete strain, A-T 11038T, was isolated from bamboo rhizospheric soil collected in Thailand. Based on a polyphasic approach, the novel strain was characterized as a member of the genus Planomonospora, which developed cylindrical to clavate sporangia containing a single motile spore on aerial mycelium. The 16S rRNA gene sequence and phylogenetic analysis indicated that strain A-T 11038T was closely related to Planomonospora sphaerica JCM 9374T (98.82 %), P.lanomonospora parontospora subsp. parontospora NBRC 13880T and P.parontospora subsp. antibiotica JCM 3094T (98.54 %), Planomonospora alba JCM 9373T (98.41 %) and Planomonospora venezuelensis JCM 3167T (97.51 %). The DNA-DNA relatedness values that distinguished strain A-T 11038T from the most closely related species were below 45 %. The novel strain contained meso-diaminopimelic acid in cell-wall hydrolysates, and rhamnose, ribose, madurose and glucose in whole-cell hydrolysates. The predominant menaquinone was MK-9(H2). The diagnostic phospholipids were diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannosides, phosphatidylinositol and aminophosphoglycolipids. The predominant cellular fatty acids were unsaturated fatty acids C17 : 1 and C16 : 1 and saturated fatty acid C16 : 0. The G+C content of the genomic DNA was 73.5 mol%. Following the evidence obtained using a polyphasic approach, the novel strain is proposed as a representative of a novel species to be named Planomonospora corallina sp. nov. The type strain is A-T 11038T (=BCC 67829T=TBRC 4489T=NBRC 110609T).

Actinoplanes luteus sp. nov., isolated from soil.

A novel filamentous bacterial strain, A-T 5190T, which developed irregular sporangia at the end of sporangiophores on substrate mycelia, was isolated from dry evergreen forest soil collected in Thailand. The 16S rRNA gene sequence and phylogenetic analysis indicated that strain A-T 5190T belonged to the genus Actinoplanes and was related most closely to Actinoplanes palleronii NBRC 14916T (98.88 % similarity) and Actinoplanes rectilineatus NBRC 13941T (98.54 %). DNA-DNA relatedness values between strain A-T 5190T and its closest relatives were below 70 %. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained rhamnose, ribose, galactose and xylose. The predominant menaquinone was MK-9(H4). The diagnostic phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The predominant cellular fatty acids were unsaturated fatty acid C17 : 1 and branched fatty acids iso-C16 : 0, iso-C15 : 0 and anteiso-C17 : 0. The G+C content of the genomic DNA was 71.9 mol%. Evidence from phenotypic, chemotaxonomic and genotypic studies indicate that strain A-T 5190T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes luteus sp. nov. is proposed. The type strain is A-T 5190T ( = BCC 41582T = NBRC 109644T).

Sinosporangium fuscum sp. nov., isolated from soil.

A novel actinomycete, A-T 8343T was isolated from a moist evergreen forest soil sample collected in the Trat Province, Thailand. Based on 16S rRNA gene sequence analysis, strain A-T 8343T belonged to the genus Sinosporangium and was closely related to Sinosporangium siamense A-T 1946T (98.81 %) and Sinosporangium album 6014T (98.54 %). The DNA-DNA relatedness values were 21.8-27 % with S. siamense A-T 1946T and 31.1-31.9 % with S. album 6014T, which were significantly below 70 %. The result differentiated A-T 8343T from the closest species. The organism developed spherical sporangia containing non-motile spores on aerial mycelia. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained rhamnose, ribose, madurose and glucose. The predominant menaquinones were MK-9(H2) and MK-9(H4). The diagnostic phospholipids were phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxyl-phosphatidylethanolamine, diphosphatidylglycerol, lyso-phosphatidylethanolamine, N-acetylglucosamine-containing phospholipids, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol-mannosides, aminophosphoglycolipid and one unknown phospholipid. The major cellular fatty acids were saturated C16 : 0, iso C16 : 0, unsaturated C16 : 1 and C18 : 1. Following an evaluation of phenotypic, chemotaxonomic and genotypic characteristics, the new isolate is proposed as a representative novel species of the genus Sinosporangium to be named Sinosporangiumfuscum sp. nov. The type strain is A-T 8343T ( = BCC 52770T = NBRC 109516T).

Sinosporangium siamense sp. nov., isolated from soil and emended description of the genus Sinosporangium.

An actinomycetes strain A-T 1946(T) that developed spherical sporangia containing non-motile spores on aerial mycelia was isolated from dry deciduous forest soil in Thailand. 16S rRNA gene sequence analysis indicated that strain A-T 1946(T) belongs to the genus Sinosporangium, being closely related to Sinosporangium album 6014(T) (98.8% sequence similarity). The DNA-DNA relatedness values were 43.7-50.9%, which were significantly below 70% and differentiated strain A-T 1946(T) from the closest species. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained rhamnose, ribose, madurose and glucose. The predominant menaquinone was MK-9(H2). The diagnostic phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, lysophosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol-mannoside, N-acetylglucosamine-containing phospholipids, two unknown phosphoglycolipids and two unknown phospholipids. The predominant cellular fatty acids were unsaturated C(16 : 1) and C(17 : 1), and saturated C(16 : 0) and 10-methyl-C(17 : 0). Following an evaluation of phenotypic, chemotaxonomic and genotypic characteristics, the isolate is proposed to represent a novel species of genus Sinosporangium to be named Sinosporangium siamense sp. nov. The type strain is A-T 1946(T) ( = BCC 29081(T) = NBRC 109515(T)). An emended description of the genus Sinosporangium is also provided.

Planobispora takensis sp. nov., isolated from soil.

A novel Gram-stain-positive, filamentous bacterial strain (A-T 7458(T)) was isolated from soil collected from hill evergreen forest in Thailand. The strain developed cylindrical sporangia containing a longitudinal pair of motile spores, on short ramifications of aerial mycelia. From a taxonomic study using a polyphasic approach, strain A-T 7458(T) had typical characteristics of members of the genus Planobispora. 16S rRNA gene sequence analysis indicated that the isolate was closely related to Planobispora siamensis A-T 4600(T) (98.5 %), Planobispora rosea JCM 3166(T) (97.6 %) and Planobispora longispora NBRC 13918(T) (97.6 %). The DNA-DNA relatedness values, which differentiated the novel strain from the closest species, were significantly below 70 %. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose, madurose, mannose and glucose. The predominant menaquinone was MK-9(H2). The diagnostic phospholipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol, phosphatidylinositol-mannoside and aminophosphoglycolipid. The predominant cellular fatty acids were unsaturated C17 : 1 and C18 : 1, and saturated C16 : 0 and C17 : 0. Following an evaluation of phenotypic, chemotaxonomic and genotypic characteristics, the novel isolate is proposed to represent a novel species of the genus Planobispora, to be named Planobispora takensis sp. nov. The type strain is A-T 7458(T) ( = BCC 48396(T) = NBRC 109077(T)).

Actinoplanes siamensis sp. nov., isolated from soil.

A Gram-positive filamentous bacterial strain that developed large campanulate sporangia at the ends of sporangiophores on substrate mycelium was isolated from bamboo forest soil in Thailand. According to the results of a polyphasic taxonomic study, our isolate had typical characteristics of members of the genus Actinoplanes. The 16S rRNA gene sequence analysis also indicated that strain A-T 6646(T) belonged to the genus Actinoplanes, being most closely related to Actinoplanes liguriensis DSM 43865(T) (97.61 %) and Actinoplanes octamycinicus NBRC 14524(T) (97.52 %). The DNA-DNA relatedness values, which differentiate the new strain from the most closely related species, were significantly below 70 %. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained xylose and arabinose. The predominant menaquinone was MK-9(H4). The diagnostic phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The predominant cellular fatty acids were iso-C16 : 0, anteiso-C17 : 0, iso-C15 : 0 and anteiso-C15 : 0. Following an evaluation of phenotypic, chemotaxonomic and genotypic studies, the isolate is proposed to represent a novel species to be named Actinoplanes siamensis sp. nov. The type strain is A-T 6646(T) (= BCC 46194(T) = NBRC 109076(T)).

Planobispora siamensis sp. nov., isolated from soil.

A novel actinomycete strain, A-T 4600(T), which developed cylindrical sporangia containing a longitudinal pair of motile spores forming singly or in bundles on short ramifications of the aerial mycelium, was isolated from soil collected from an evergreen forest in Thailand. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose, madurose, mannose and glucose. The predominant menaquinones were MK-9(H2). Mycolic acids were not detected. The diagnostic phospholipids were phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol, phosphatidylglycerol, phosphatidylinositol mannoside, diphosphatidylglycerol and aminophosphoglycolipid. The predominant cellular fatty acids were unsaturated C17 : 1, C18 : 1, saturated C16 : 0, and C17 : 0. The G+C content of the DNA was 70.8 mol%. Phenotypic and chemotaxonomic analyses showed that the isolate had the typical characteristics of members of the genus Planobispora. Furthermore, 16S rRNA gene sequence analysis also indicated that this strain belonged to the genus Planobispora but as a putative novel species. DNA-DNA relatedness values that differentiate the isolate from previously described members of the genus Planobispora were significantly below 70 %. Following an evaluation of phenotypic, chemotaxonomic and genotypic studies, it is proposed that the isolate represents a novel species, Planobispora siamensis sp. nov.; the type strain is A-T 4600(T) ( = BCC 39469(T) = NBRC 107568(T)).

Kutzneria buriramensis sp. nov., isolated from soil, and emended description of the genus Kutzneria.

A Gram-staining-positive, filamentous bacterium, which developed large globose sporangia at the ends of long sporangiophores on aerial mycelium, was isolated from dry soil collected in a deciduous forest in Thailand. The cell-wall peptidoglycan of the novel bacterium, which was designated strain A-T 1846(T), contained meso-diaminopimelic acid and the whole-cell sugars comprised rhamnose, ribose, mannose, glucose and galactose. The predominant menaquinone was MK-9(H(4)). Mycolic acids were not detected. The identified phospholipids were phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxyphosphatidylethanolamine, phosphatidylinositol, phosphatidylglycerol and diphosphatidylglycerol. The predominant cellular fatty acids were iso-C(16:0), iso-C(16 : 0) 2-OH and C(16 : 0) 10-methyl. The G+C content of the genomic DNA was 72 mol%. The phenotypic and chemotaxonomic characteristics of the novel strain resembled those of established members of the genus Kutzneria. Phylogenetic analyses based on 16S rRNA gene sequences also indicated that this strain belonged to the genus Kutzneria but as a representative of a putative novel species. In hybridization experiments, the DNA-DNA relatedness values recorded between the novel strain and established members of the genus Kutzneria all fell well below 70 %. Based on the phenotypic, chemotaxonomic and genotypic evidence and the results of the DNA-DNA hybridizations, strain A-T 1846(T) represents a novel species in the genus Kutzneria, for which the name Kutzneria buriramensis sp. nov. is proposed. The type strain is A-T 1846(T) (=BCC 29373(T) =NBRC 107931(T)). An emended description of the genus Kutzneria is provided.

Chemical taxonomy of Torrubiella s. lat.: zeorin as a marker of Conoideocrella.

The insect pathogens in the genus Torrubiella s. lat. were recently divided into new genera based on molecular phylogenetic characters. Isolates collected at various locations in Thailand, were tested for their productivity of a hopane-type triterpene, zeorin (6α,22-dihydroxyhopane), when cultured in potato dextrose broth under static conditions. Among the 49 strains of Torrubiella s. lat. species, Conoideocrella luteorostrata (ten strains) and C. tenuis (seven strains), all collected on scale insects (Hemiptera), produced zeorin, whereas another six strains of Orbiocrella petchii (which was recently removed from Torrubiella) failed in the detection of this secondary metabolite. All other Torrubiella s. lat. (26 strains), collected on other insect hosts including leafhoppers (eight strains), Lepidoptera (one strain), and spiders (17 strains), produced no detectable zeorin. Paecilomyces cinnamomeus (nine strains), the anamorph of C. luteorostrata, also produced zeorin. These results correspond with the recent taxonomic reclassification based on multigene phylogeny.

Sphaerisporangium krabiense sp. nov., isolated from soil.

A Gram-staining-positive, filamentous bacterial strain, designated A-T 0308(T), was isolated from soil of a tropical mangrove forest in Thailand. Strain A-T 0308(T) developed spherical sporangia containing non-motile spores on aerial mycelium. The novel strain contained meso-diaminopimelic acid, N-acetyl-type peptidoglycan and madurose, mannose, ribose, galactose and glucose as whole-cell sugars. The predominant menaquinones were MK-9(H(4)) and MK-9(H(6)); a small amount of MK-9(H(2)) and MK-9 was also detected. Mycolic acids were not detected. The diagnostic phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and phosphoglycolipid. The predominant cellular fatty acids were iso-C(16:0) and 10-methylated C(17:0). The G+C content of the DNA was 72 mol%. Phenotypic and chemotaxonomic analyses showed that the novel isolate had characteristics typical of members of the genus Sphaerisporangium. 16S rRNA gene sequence analysis also indicated that the strain belongs to the genus Sphaerisporangium and that it represents a clade distinct from other members of the genus with sequence similarities ranging from 96.3 to 97.8% between the novel strain and its closest relatives. Based on the results of phenotypic, chemotaxonomic and phylogenetic studies, strain A-T 0308(T) (=BCC 21702(T) =NBRC 107571(T)) represents a novel species of the genus Sphaerisporangium, for which the name Sphaerisporangium krabiense sp. nov. is proposed.