Publications by authors named "Chanita Boonmak"

We have accidentally found that a thermophilic Geobacillus kaustophilus HTA426 is capable of degrading alkanes although it has no alkane oxygenating enzyme genes. Our experimental results revealed that a putative ribonucleotide reductase small subunit GkR2loxI (GK2771) gene encodes a novel heterodinuclear Mn-Fe alkane monooxygenase/hydroxylase. GkR2loxI protein can perform two-electron oxidations similar to homonuclear diiron bacterial multicomponent soluble methane monooxygenases.

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Duckweed-associated actinobacteria are co-existing microbes that affect duckweed growth and adaptation. In this study, we aimed to report a novel actinobacterium species and explore its ability to enhance duckweed growth. Strain DW7H6 was isolated from duckweed, Lemna aequinoctialis.

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Duckweed has been highlighted as an invaluable resource because of its abilities to remove nitrogen and phosphorus from wastewater coupling with the production of high starch/protein-containing plant biomass. Duckweed recruits microbes and particularly forms a stable "core" bacterial microbiota, which greatly reduces the colonization efficiency of plant growth-promoting bacteria (PGPB). In this study, natural duckweeds were enriched in a sterilized-partially treated wastewater effluent from a poultry farm.

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Microbially induced calcium carbonate precipitation (MICP) has been highlighted for its application in civil engineering, and in the environmental and geotechnical fields. Ureolytic activity is one of the most promising bacterial mechanisms in terms of inducing calcium carbonate formation. In this study, four bacterial isolates with high-yield urease production capabilities were obtained from two-step screening using a high-buffered urea medium.

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The advantages of aquatic biomass production using wastewater as a cost-free fertilizer have recently been highlighted. Here, we report a successful study in which duckweed, Lemna gibba, biomass production in a food factory effluent containing low nitrogen and high salts was enhanced by employing customized plant growth-promoting bacteria (PGPB). Two common PGPB strains previously obtained from natural pond water, Acinetobacter calcoaceticus P23 and Pseudomonas fulva Ps6, hardly promoted the growth of duckweed; on the contrary, they inhibited its growth in treated factory wastewater, far different water conditions.

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Two strains (DMKU-GTCP10-8 and CLIB 1740) representing a novel anamorphic yeast species were isolated from a grease sample collected from a grease trap in Thailand and from an unidentified fungus collected in French Guiana, respectively. On the basis of phylogenetic analysis based on the combined D1D2 domain of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, CBS 707 was the closely related species with 12.8 % sequence divergence (70 nucleotide substitutions and three gaps in 571 nucleotides) and 28.

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Seven yeast strains, DMKU VGT1-14, DMKU VGT1-19, DMKU-JMGT1-28, DMKU-JMGT1-32, DMKU VGT2-06, DMKU VGT2-19 and DMKU VGT6-14, were isolated from a grease trap in Thailand and two strains, SJ-1 and SN-102 were isolated from the sea surface microlayer in Taiwan. On the basis of phenotypic characteristics and sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, these strains represented two novel yeast species of the genus . In terms of pairwise sequence similarity, four strains, DMKU VGT1-14, DMKU-JMGT1-32, DMKU VGT6-14 and SN-102, were closely related to NRRL Y-17858 but differed by 13 nucleotide substitutions with one gap (2.

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A total of 175 yeast isolates were obtained from grease samples. Based on the D1/D2 region of the large subunit (LSU) ribosomal RNA (rRNA) gene analysis, 150 yeast isolates were identified as belonging to 36 described yeast species, whereas 25 isolates required more analysis. Among the described species, was the only Basidiomycetous yeast, whereas 149 isolates were identified as belonging to 35 described species of 15 genera in the phylum Ascomycota, and was the most abundant species.

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Two yeast strains, DMKU-WBL1-3 and DMKU GT3-16, were obtained from grease samples collected from grease traps at the Kasetsart University canteen, Thailand. Pairwise sequence analysis indicated that the strains were closely related to NRRL Y-17506, but differed by 11 and 35 nucleotide substitutions in the D1/D2 domain of the large subunit (LSU) rRNA gene and the ITS region, respectively. Based on sequence divergences, the novel species was distinguished from .

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Khanthuli peat swamp forest (PSF) is one of a few fertile peat swamp forests that remain in Thailand. It is composed of primary PSF and some areas which have been degraded to secondary PSF due to drought, wildfires and land conversion, which have resulted in a decrease in peat layers and change in the species of the plant community. In this study, diversity of yeasts in peat from both primary and secondary PSF areas of the Khanthuli PSF was determined based on culture-dependent approaches, using dilution plate and enrichment techniques.

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Strain DMKU-SP105 representing a novel yeast species was isolated from the external surface of a sugarcane leaf (Saccharum officinarum L.) collected from a sugarcane plantation field in Phichit province, Thailand. On the basis of sequence analysis of the D1/D2 region of the large subunit (LSU) rRNA gene and the internal transcribed spacer (ITS) region, the strain DMKU-SP105 differed by 7-16 substitutions in the D1/D2 region of LSU rRNA gene and 6-22 substitutions in the ITS region from a group of related species, Papiliotrema aspenensis, Papiliotrema odontotermitis, Papiliotrema rajasthanensis and Papiliotrema laurentii.

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An extremely thermophilic bacterium, Geobacillus thermoleovorans B23, is capable of degrading a broad range of alkanes (with carbon chain lengths ranging between C11 and C32) at 70 °C. Whole-genome sequence analysis revealed that unlike most alkane-degrading bacteria, strain B23 does not possess an alkB-type alkane monooxygenase gene. Instead, it possesses a cluster of three ladA-type genes, ladAαB23, ladAβB23, and ladB B23, on its chromosome, whose protein products share significant amino acid sequence identities, 49.

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A thermotolerant ammonia-oxidizing bacterium strain JPCCT2 was isolated from activated sludge in a thermal power station. Cells of JPCCT2 are short non-motile rods or ellipsoidal. Molecular phylogenetic analysis of 16S rRNA gene sequences demonstrated that JPCCT2 belongs to the genus Nitrosomonas with the highest similarity to Nitrosomonas nitrosa Nm90 (100%), Nitrosomonas sp.

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Here, we report the draft genome sequence of Geobacillus thermoleovorans strain B23, which was isolated from a deep subterranean petroleum reservoir in Japan. An array of genes related to unique long-chain alkane degradation pathways in G. thermoleovorans B23 has been identified by whole-genome analyses of this strain.

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Xylan is a major component of hemicellulose, which constitutes about 40 % of plant biomass. Hydrolysis of xylan into simple sugars is one of the important steps in the conversion of lignocellulosic material to value-added products. During an investigation of cellulose- and xylan-degrading yeasts, two yeast strains that were able to use cellulose and xylan as sole carbon source were found to represent a phylogenetically distinct species in the Spathaspora clade.

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Four strains of two novel xylose-utilizing yeast species were obtained from samples collected in Thailand from decaying corncobs (strains KU-Xs13(T) and KU-Xs18), a decaying grass (KU-Xs20) and estuarine water from a mangrove forest (WB15(T)). On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics and sequence analysis of the D1/D2 domain of the large subunit rRNA gene, the four strains were found to represent two novel species of the genus Candida in the Candida albicans/Lodderomyces elongisporus clade. Three strains (KU-Xs13(T), KU-Xs18 and KU-Xs20) were assigned as a single novel species, which was named Candida saraburiensis sp.

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Nine strains of three novel anamorphic yeast species were obtained from samples collected in Thailand including six strains (RV96, RV152, R14, RS9, RS58 and EA1) obtained from estuarine waters collected from two mangrove forests, one strain (ST84) from insect frass and two strains (SR16 and UB13) from forest soils. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, and the sequence analysis of the D1/D2 domain of the large subunit rRNA gene, the nine strains were found to represent three novel Candida species in the Saturnispora clade. Five strains (RV96, RV152, R14, RS9 and RS58) were assigned as a single novel species, which was named Candida sanitii sp.

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Three strains of a novel anamorphic yeast species were isolated from natural samples collected in Thailand, including strain EF10 isolated from sediment in a mangrove forest, strain ST-473 from rotten wood, and strain ST-479 from a wild mushroom (Hygrophorus sp.). Analysis of the D1/D2 domains of the large-subunit rRNA gene sequence revealed that the sequence of strain EF10 differed from the other two strains (ST-473 and ST-479), which had identical sequences, by only one nucleotide (nt) substitution in 535 nt.

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