Kannika Duangmal

Pseudonocardia acaciae sp. nov., isolated from roots of Acacia auriculiformis A. Cunn. ex Benth.

A novel Gram-positive-staining actinomycete designated strain GMKU095(T) was isolated from surface-sterilized roots of Acacia auriculiformis A. Cunn. ex Benth. (earpod wattle). The organism produced branching mycelium. The spores were non-motile and had a spiny surface. Growth of strain GMKU095(T) occurred at 18-42 degrees C, pH 5.0-8.0 and at NaCl concentrations up to 5 %. Whole-cell hydrolysates contained arabinose and galactose as major characteristic sugars. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. The glycan moiety of the murein contained acetyl residues. The menaquinone was MK-8(H(4)); mycolic acids were not detected. The G+C content of the DNA was 71.6 mol%. iso-C(16 : 0) was detected as the major cellular fatty acid. Comparative studies of 16S rRNA gene sequences indicated that the strain was phylogenetically related to members of the genus Pseudonocardia. The most closely related type strain is Pseudonocardia spinosispora IMSNU 50581(T), which is 96.2 % similar in 16S rRNA gene sequence. On the basis of the genotypic and phenotypic properties presented, a novel species of the genus Pseudonocardia is proposed, Pseudonocardia acaciae sp. nov. The type strain is strain GMKU095(T) (=NRRL B-24609(T) =BCC 28481(T) =TISTR 1862(T) =NBRC 104274(T)).

Acidophilic actinomycetes from rhizosphere soil: diversity and properties beneficial to plants

Three hundred and fifty-one isolates of actinomycetes were recovered from 21 rhizospheric soil samples using acidified media of pH 5.5. They were evaluated for their antifungal, siderophore production and phosphate solubilization activities. The total count of actinomycetes growing on acidified starch casein agar and Gause no. 1 agar were below 2.48 × 104 CFU g−1 soil. Two hundred and twelve isolates were assigned to acidophiles and the remaining 139 isolates were neutrophiles. Of these actinomycetes, 57.8, 32.5 and 50.4%, showed antagonistic activity against three rice pathogenic fungi; Fusarium moniliforme, Helminthosporium oryzae and Rhizoctonia solani, respectively. More than half of the isolates (68.1%) inhibited at least one tested pathogenic fungus, whereas 25.9% exhibited antifungal activities against all tested fungi. Three hundred and thirty-eight isolates (96.3%) produced siderophore and 266 isolates (75.8%) solubilized phosphate. A greater proportion of the acidophilic actinomycetes exhibited antifungal, siderophore production and phosphate solubilization activity compared with the neutrophiles. Three hundred and twenty-five isolates (92.6%) were classified as streptomycetes based on their morphological characteristics and the presence of the LL-isomeric form of diaminopimelic acid in whole-cell hydrolysates. The 16S ribosomal RNA (rRNA) gene analysis of representative non-streptomycete strains showed that the isolates belonged to seven genera, that is, Allokutzneria, Amycolatopsis, Mycobacterium, Nocardia, Nonomuraea, Saccharopolyspora and Verrucosispora. The potential antifungal acidophilic isolates, R9-4, R14-1, R14-5 and R20-5, showed close similarity to Streptomyces misionensis NBRC 13063T (AB184285) in terms of morphological characteristics and 16S rRNA gene sequences.

Nonomuraea syzygii sp. nov., an endophytic actinomycete isolated from the roots of a jambolan plum tree (Syzygium cumini L. Skeels).

A novel endophytic actinomycete, designated strain GKU 164(T), was isolated from the roots of a jambolan plum tree (Syzygium cumini L. Skeels), collected at Khao Khitchakut National Park, Chantaburi province, Thailand. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain formed a distinct clade within the genus Nonomuraea , and was most closely related to Nonomuraea monospora PT708(T) (98.77% 16S rRNA gene sequence similarity) and Nonomuraea thailandensis KC-061(T) (98.73%). Strain GKU 164(T) formed a branched substrate and aerial hyphae that generated single spores with rough surfaces. The cell wall contained meso-diaminopimelic acid. The whole-cell sugars were madurose, galactose, mannose, ribose, rhamnose and glucose. The N-acyl type of muramic acid was acetyl. The predominant menaquinone was MK-9(H4) with minor amounts of MK-9(H6), MK-9(H2) and MK-9(H0). The phospholipid profile contained diphosphatidylglycerol, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositolmannosides, phosphatidylmonomethylethanolamine, hydroxy-phosphatidylmonomethylethanolamine, an unidentified aminophosphoglycolipid and four unknown phospholipids. The major fatty acids were iso-C(16 : 0) and 10-methyl C(17 : 0). The genomic DNA G+C content was 70.4 mol%. Significant differences in the morphological, chemotaxonomical, and biochemical data together with DNA-DNA relatedness values between strain GKU 164(T) and type strains of closely related species, clearly demonstrated that strain GKU 164(T) represents a novel species of the genus Nonomuraea , for which the name Nonomuraea syzygii sp. nov. is proposed. The type strain is GKU 164(T) ( = BCC 70457(T) = NBRC 110400(T)).

Kineococcus gynurae sp. nov., isolated from a Thai medicinal plant.

A novel, Gram-positive, motile, coccus-shaped, orange-pigmented organism, designated strain KKD096(T), was isolated from the roots of a Thai medicinal plant, Gynura pseudochina DC. var. hispida Thwaites. Growth of strain KKD096(T) occurred at temperatures of 14-34 degrees C, at pH 5.0-9.0 and at NaCl concentrations up to 7 % (w/v). Whole-cell hydrolysates contained arabinose and galactose as the characteristic sugars. The diagnostic diamino acid of the peptidoglycan was meso-diaminopimelic acid. The glycan moiety of the murein contained acetyl residues. The predominant menaquinone was MK-9(H2); mycolic acids were not detected. The genomic DNA G+C content was 73.3 mol%. The major cellular fatty acid was anteiso-C(15 : 0) (81.42 % of the total). Strain KKD096(T) was assigned to the genus Kineococcus on the basis of 16S rRNA gene sequence analysis; it was most closely related to Kineococcus radiotolerans DSM 14245(T) (97.1 % similarity). DNA-DNA hybridization revealed 39.4 % relatedness between these two taxa. On the basis of the genotypic and phenotypic data presented, strain KKD096(T) is considered to represent a novel species of the genus Kineococcus, for which the name Kineococcus gynurae sp. nov. is proposed. The type strain is KKD096(T) (=TISTR 1856(T)=NRRL B-24568(T)=BCC 26245(T)=NBRC 103943(T)).

Amycolatopsis samaneae sp. nov., isolated from roots of Samanea saman (Jacq.) Merr.

A novel actinomycete, designated strain RM287(T), was isolated from surface-sterilized roots of Samanea saman (Jacq.) Merr., collected from Bangkok, Thailand. The status of the novel strain was determined using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the organism formed a distinct phyletic line within the radiation of the genus Amycolatopsis. The 16S rRNA gene sequence similarity indicated that strain RM287(T) was most closely related to Amycolatopsis mediterranei IMSNU 20056(T) (97.4 %), A. rifamycinica DSM 46095(T) (97.2 %), A. kentuckyensis NRRL B-24129(T) (97.2 %), A. pretoriensis DSM 44654(T) (97 %) and A. australiensis DSM 44671(T) (97 %). The novel organism was found to have chemical properties typical of members of the genus Amycolatopsis such as meso-diaminopimelic acid as the dignostic diamino acid in the cell-wall peptidoglycan and arabinose and galactose as the diagnostic sugars. The major menaquinone was MK-9(H(4)). The major fatty acids were iso-C(16 : 0) iso-C(15 : 0), iso 2-OH-C(16 : 0) and iso-C(17 : 0). The DNA G+C content was 71.7 mol%. Phenotypic data clearly distinguished the novel isolate from its closest relatives. The combined genotypic and phenotypic data indicated that strain RM287(T) represented a novel species of the genus Amycolatopsis. The proposed name for this organism is Amycolatopsis samaneae sp. nov., with the type strain RM287(T) ( = TISTR 1919(T) = BCC 35842(T) = NBRC 106095(T)).

Sphaerisporangium rufum sp. nov., an endophytic actinomycete from roots of Oryza sativa L.

An endophytic actinomycete, strain R10-82(T), isolated from surface-sterilized roots of rice (Oryza sativa L.) was studied using a polyphasic approach. Strain R10-82(T) produced branching substrate mycelia and developed spherical spore vesicles on aerial hyphae containing non-motile spores. The major cellular fatty acids were iso-C16 : 0, iso-C14 : 0 and 10-methyl C17 : 0. The predominant menaquinones were MK-9, MK-9(H2), MK-9(H4) and MK-9(H6). Rhamnose, ribose, madurose, mannose and glucose were detected in whole-cell hydrolysates. The diagnostic phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol mannosides, hydroxylphosphatidylethanolamine and ninhydrin-positive phosphoglycolipids. These morphological and chemotaxonomic data were similar to those of the genus Sphaerisporangium. Analysis of the 16S rRNA gene sequence revealed that strain R10-82(T) was related most closely to Sphaerisporangium cinnabarinum JCM 3291(T) (98.3 % similarity). The DNA G+C content of strain R10-82(T) was 74 mol%. DNA-DNA relatedness data in combination with differences in the biochemical and physiological properties suggested that strain R10-82(T) should be classified as representing a novel species of the genus Sphaerisporangium, for which the name Sphaerisporangium rufum is proposed. The type strain is R10-82(T) ( = BCC 51287(T) = NBRC 109079(T)). An emended description of the genus Sphaerisporangium is also provided.

Actinoallomurus acaciae sp. nov., an endophytic actinomycete isolated from Acacia auriculiformis A. Cunn. ex Benth.

A novel endophytic actinomycete, strain GMKU 931(T), was isolated from the root of a wattle tree, Acacia auriculiformis A. Cunn. ex Benth., collected at Kasetsart University, Bangkok, Thailand. Strain GMKU 931(T) produced short spiral chains of smooth-surfaced spores on the aerial mycelium. Lysine and meso-diaminopimelic acid were present in the cell-wall peptidoglycan. Whole-cell hydrolysates contained galactose, madurose and mannose. The predominant menaquinones were MK-9(H(6)) and MK-9(H(8)). The major fatty acids were iso-C(16 : 0) and iso-C(16 : 1). The major phospholipids were phosphatidylinositol and phosphatidylglycerol. A phylogenetic analysis based on 16S rRNA gene sequences suggested that strain GMKU 931(T) forms a distinct phyletic line within the recently proposed genus Actinoallomurus. The significant differences in phenotypic and genotypic data indicate that strain GMKU 931(T) represents a novel species of the genus Actinoallomurus, for which the name Actinoallomurus acaciae sp. nov. is proposed. The type strain is GMKU 931(T) (=BCC 28622(T) =NBRC 104354(T) =NRRL B-24610(T)).

Roseomonas elaeocarpi sp. nov., isolated from olive (Elaeocarpus hygrophilus Kurz.) phyllosphere.

An aerobic, Gram-stain-negative, coccobacillus-shaped, non-endospore-forming, pink-pigmented bacterium, designated PN2T, was isolated from an olive leaf. The strain grew at 15-35 °C with an optimum temperature for growth at 30 °C, and at pH 5.0-7.5 with an optimum pH for growth at 6.0. Growth was observed in the presence of up to 1.02 % (w/v) NaCl. The major fatty acids were C19 : 0 cyclo ω8c, C16 : 0 and C18 : 1ω7c. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, unknown aminolipids, an unknown phospholipid and an unknown lipid. The respiratory quinone was ubiquinone-10. The DNA G+C content of strain PN2T was 70.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain PN2T was closely related to members of the genus Roseomonas and shared highest similarity with Roseomonas mucosa ATCC BAA-692T (96.5 %), Roseomonas gilardii subsp. gilardii ATCC 49956T (96.2 %) and Roseomonas gilardii subsp. rosea ATCC BAA-691T (96.2 %). Furthermore, the DNA-DNA relatedness value between strain PN2T and the closest related species R. mucosa ATCC BAA-692T was 27 %. These data allowed the phenotypic and genotypic differentiation of strain PN2T from its closest phylogenetic neighbour (R. mucosa ATCC BAA-692T). Based on phenotypic and genotypic characteristics, strain PN2T is classified as representing a novel species of the genus Roseomonas for which the name Roseomonas elaeocarpi sp. nov. is proposed. The type strain is PN2T ( = BCC 44864T = NBRC 107871T).

Microbispora thailandensis sp. nov., an actinomycete isolated from cave soil.

The taxonomic position of actinomycete strain NN276T, isolated from cave soil, was studied using the polyphasic taxonomic approach. A phylogenetic tree based on 16S ribosomal RNA (rRNA) gene sequences showed that the isolate formed a distinct evolutionary linage with the genus Microbispora, with M. mesophila JCM 3151T as its closest phylogenetic neighbor (97.9% similarity). The organism contained meso-diaminopimelic acid and the N-acetyl type of peptidoglycan. Madurose was detected in the whole-cell hydrolasate. The predominant menaquinones were MK-9(H4), MK-9(H2) and MK-9. Mycolic acids were not detected. Major phospholipids were diphosphatidylglycerol, hydroxy-phosphatidylethanolamine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The major cellular fatty acid was iso-C16: 0 and G+C content 70 mol%. DNA–DNA hybridization demonstrated that the isolate was distinct from M. mesophila JCM 3151T. On the basis of phenotypic and genotypic data, it is proposed that strain NN276T represents a novel species of the genus Microbispora, hence the name Microbispora thailandensis sp. nov. The type strain is strain NN276T (=BCC 41490T=NRRL B-24806T=NBRC 107569T).

Streptomyces oryzae sp. nov., an endophytic actinomycete isolated from stems of rice plant

An actinomycete strain S16–07T, isolated from surface-sterilized stems of rice plant (Oryza sativa L.), was characterized using a polyphasic approach. Phylogenetic analysis of 16S rRNA gene sequences indicated affiliation of the strain belonged to the genus Streptomyces. The highest levels of sequence similarity were found with Streptomyces smyrnaeus SM3501T (97.7% similarity), S. abikoensis NBRC 13860T (97.6% similarity) and S. thermocarboxydovorans NBRC 16324T (97.5% similarity). The cell wall of strain S16–07T contained LL-diaminopimelic acid. The predominant menaquinones were MK-9(H6) and MK-9(H8). Phospholipids detected were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, hydroxy-phosphatidylethanolamine, hydroxy-phosphatidylmonomethylethanolamine and phosphatidylinositol mannosides. The major cellular fatty acids were ai-C15:0, i-C16:0 and ai-C17:0. The G+C content of strain S16–07T was 70.4 mol%. On the basis of the phylogeny of the isolate and its differences from the most closely related species, the isolate S16–07T represents a novel species for which the name S. oryzae sp. nov. is proposed. The type strain is S16–07T (=BCC 60400T=NBRC 109761T).