11 results on '"Wittaya Tawong"'
Search Results
2. Amazonocrinis thailandica sp. nov. (Nostocales, Cyanobacteria), a novel species of the previously monotypic Amazonocrinis genus from Thailand
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Wittaya Tawong, Pongsanat Pongcharoen, Piyawat Pongpadung, Supat Ponza, and Weerachai Saijuntha
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Plant Science ,Aquatic Science ,Ecology, Evolution, Behavior and Systematics - Abstract
Cyanobacteria are distributed worldwide, and many new cyanobacterial species are discovered in tropical region. TheNostoc-like genus Amazonocrinis has been separated from the genus Nostoc based on polyphasic methods. However,species diversity within this genus remains poorly understood systematically because only one species (Amazonocrinisnigriterrae) has been described. In this study, two novel strains (NUACC02 and NUACC03) were isolated from moist ricefield soil in Thailand. These two strains were characterized using a polyphasic approach, based on morphology, 16S rRNAphylogenetic analysis, internal transcribed spacer secondary structure and ecology. Phylogenetic analyses based on 16SrRNA gene sequences confirmed that the two novel strains formed a monophyletic clade related to the genus Amazonocrinisand were distant from the type species A. nigriterrae. The 16S rRNA gene sequence similarity (
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- 2022
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3. Molecular characterizations of Thai Raphidiopsis raciborskii (Nostocales, Cyanobacteria) based on 16S rDNA, rbcLX, and cylindrospermopsin synthetase genes
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Pongsanat Pongcharoen, Masao Adachi, Tomohiro Nishimura, and Wittaya Tawong
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Nostocales ,Cyanobacteria ,Genetics ,Ecology ,biology ,Raphidiopsis ,Aquatic Science ,Oceanography ,biology.organism_classification ,16S ribosomal RNA ,chemistry.chemical_compound ,chemistry ,Cylindrospermopsin ,Gene ,Ecology, Evolution, Behavior and Systematics - Published
- 2019
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4. First report on okadaic acid production of a benthic dinoflagellate Prorocentrum cf. fukuyoi from Japan
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Wittaya Tawong, Tomohiro Nishimura, Masao Adachi, Toshiyuki Suzuki, Hajime Uchida, Shota Abe, and Shingo Arimitsu
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0106 biological sciences ,biology ,Strain (chemistry) ,Phylogenetic tree ,010604 marine biology & hydrobiology ,Dinoflagellate ,Zoology ,Subclade ,Plant Science ,Okadaic acid ,Aquatic Science ,biology.organism_classification ,medicine.disease ,010603 evolutionary biology ,01 natural sciences ,Agricultural and Biological Sciences (miscellaneous) ,Shellfish poisoning ,chemistry.chemical_compound ,chemistry ,Phylogenetics ,medicine ,Shellfish - Abstract
The consumption of bivalves contaminated with diarrhetic shellfish toxins (DSTs) such as okadaic acid and dinophysistoxins has caused serious economic hardship to shellfish industries worldwide including Japan. Several benthic species of the genus Prorocentrum have been confirmed to produce DSTs. There have been no published studies of Japanese strains of Prorocentrum species that include a three‐way characterization of morphological characteristics, molecular phylogenetic data, and toxin profiles. In the present study, a benthic Prorocentrum strain isolated from Japanese temperate shallow water (depths
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- 2019
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5. Abundance and seasonal population dynamics of the potentially ciguatera-causing dinoflagellate Gambierdiscus in Japanese coastal areas between 2007 and 2013
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Haruo Yamaguchi, Shota Abe, Daiki Inokuchi, Keita Uehara, Takuya Yoshioka, Takuji Ikegami, Hiroshi Sakanari, Wittaya Tawong, Tomohiro Nishimura, Masao Adachi, and Masatoshi Nakamura
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0106 biological sciences ,0301 basic medicine ,education.field_of_study ,Ciguatera ,Ecology ,biology ,010604 marine biology & hydrobiology ,Population ,Dinoflagellate ,Gambierdiscus ,Aquatic Science ,Oceanography ,medicine.disease ,biology.organism_classification ,01 natural sciences ,Salinity ,03 medical and health sciences ,Sea surface temperature ,030104 developmental biology ,Abundance (ecology) ,medicine ,education ,Ecology, Evolution, Behavior and Systematics ,Ciguatera fish poisoning - Published
- 2018
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6. Temperature and salinity effects and toxicity of Gambierdiscus caribaeus (Dinophyceae) from Thailand
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Haruo Yamaguchi, Masao Adachi, Wittaya Tawong, and Takamichi Yoshimatsu
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0106 biological sciences ,0301 basic medicine ,Gambierdiscus caribaeus ,Veterinary medicine ,Ciguatera ,biology ,Range (biology) ,010604 marine biology & hydrobiology ,Dinoflagellate ,Temperature salinity diagrams ,Environmental factor ,Plant Science ,Aquatic Science ,biology.organism_classification ,medicine.disease ,medicine.disease_cause ,01 natural sciences ,Salinity ,03 medical and health sciences ,030104 developmental biology ,Botany ,medicine ,Dinophyceae - Abstract
Species of the benthic dinoflagellate genus Gambierdiscus are the putative producer of the toxins causing ciguatera fish poisoning (CFP) in tropical and subtropical areas. Although CFP events and distribution of G. caribaeus have been reported in Thailand, little is known about the conditions that enhance the growth of Gambierdiscus in Thailand. Hence, this study was aimed at determining the effects of temperature and salinity and their interactions on the growth of Thai G. caribaeus. The strain tested showed the highest cell yield in IMK/2 medium. Based on growth rate (μ), Thai G. caribaeus grew in the temperature range of 20°C–35°C and the salinity range of 20–40. The suboptimal condition (≥ 80% of the maximal growth rate) for the strain tested was 20.5°C–30.5°C and salinity of 25.0–37.5. The optimal condition was 25°C and salinity of 30. Furthermore, the Thai G. caribaeus revealed high toxicity to mice. Our results suggest that tolerance of up to 35°C may allow these organisms to be distribute...
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- 2016
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7. Quantitative PCR assay for detection and enumeration of ciguatera-causing dinoflagellate Gambierdiscus spp. (Gonyaulacales) in coastal areas of Japan
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Hiroshi Sakanari, Haruo Yamaguchi, Wittaya Tawong, Naohito Hariganeya, Masao Adachi, and Tomohiro Nishimura
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0106 biological sciences ,Ciguatera ,Plant Science ,010501 environmental sciences ,Aquatic Science ,Real-Time Polymerase Chain Reaction ,DNA, Ribosomal ,01 natural sciences ,Gambierdiscus australes ,Microbiology ,Plasmid ,Japan ,Genus ,Abundance (ecology) ,TaqMan ,medicine ,0105 earth and related environmental sciences ,Population Density ,Phylotype ,biology ,010604 marine biology & hydrobiology ,Dinoflagellate ,Reproducibility of Results ,biology.organism_classification ,medicine.disease ,Dinoflagellida ,Environmental Monitoring - Abstract
In Japan, ciguatera fish poisoning (CFP) has been increasingly reported not only in subtropical areas but also in temperate areas in recent years, causing a serious threat to human health. Ciguatera fish poisoning is caused by the consumption of fish that have accumulated toxins produced by an epiphytic/benthic dinoflagellate, genus Gambierdiscus. Previous studies revealed the existence of five Gambierdiscus species/phylotypes in Japan: Gambierdiscus australes, Gambierdiscus scabrosus, Gambierdiscus sp. type 2, Gambierdiscus sp. type 3, and Gambierdiscus (Fukuyoa) cf. yasumotoi. Among these, G. australes, G. scabrosus, and Gambierdiscus sp. type 3 strains exhibited toxicities in mice, whereas Gambierdiscus sp. type 2 strains did not show any toxicity. Therefore, it is important to monitor the cell abundance and dynamics of these species/phylotypes to identify and characterize CFP outbreaks in Japan. Because it is difficult to differentiate these species/phylotypes by observation under a light microscope, development of a rapid and reliable detection and enumeration method is needed. In this study, a quantitative PCR assay was developed using a TaqMan probe that targets unique SSU rDNA sequences of four Japanese Gambierdiscus species/phylotypes and incorporates normalization with DNA recovery efficiency. First, we constructed standard curves with high linearity (R2=1.00) and high amplification efficiency (≥1.98) using linearized plasmids that contained SSU rDNA of the target species/phylotypes. The detection limits for all primer and probe sets were approximately 10 gene copies. Further, the mean number of SSU rDNA copies per cell of each species/phylotype was determined from single cells in culture and from those in environmental samples using the qPCR assay. Next, the number of cells of each species/phylotype in the mixed samples, which were spiked with cultured cells of the four species/phylotypes, was calculated by division of the total number of rDNA copies of each species/phylotype in each sample by the number of rDNA copies per cell. The numbers of cells of each species/phylotype quantified by qPCR assay were similar to the number of cells of each species/phylotype that were spiked. Finally, the cell densities of the target species/phylotypes were quantified using the qPCR assay in 30 environmental samples collected from Japanese coastal areas. Total cell densities of the four Gambierdiscus species/phylotypes quantified by qPCR assay were similar to those of Gambierdiscus spp. quantified by direct counting under a light microscope. The qPCR assay developed in this study is expected to be a powerful new tool for determining detailed distribution patterns and for monitoring the cell abundance and dynamics of each Japanese Gambierdiscus species/phylotype in the coastal areas of Japan.
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- 2016
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8. Effects of temperature, salinity and their interaction on growth of benthic dinoflagellates Ostreopsis spp. from Thailand
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Wittaya Tawong, Haruo Yamaguchi, Takamichi Yoshimatsu, and Masao Adachi
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Range (biology) ,Subclade ,Plant Science ,Aquatic Science ,Biology ,Salinity ,Human health ,chemistry.chemical_compound ,chemistry ,Benthic zone ,Water temperature ,Palytoxin ,Botany ,Bloom dynamics - Abstract
Benthic dinoflagellates Ostreopsis spp. are known as producers of palytoxin and its analogs, resulting occasionally in human health problems worldwide. Although distribution of Ostreopsis spp. along the Thai coasts has been reported, little is known about their growth characteristics. To discuss the bloom dynamics of Ostreopsis spp. in Thailand, first we tested four kinds of media to optimize growth conditions and then clarified the effects of temperature, salinity and temperature–salinity interaction on the growth of strains of the O. cf. ovata Thailand subclade, O. cf. ovata South China Sea subclade, Ostreopsis sp. 6 and Ostreopsis sp. 7. We showed that the f/2 medium was a suitable medium which gave the highest cell yields for all the strains tested. The strains of the O. cf. ovata Thailand subclade, O. cf. ovata South China Sea subclade and Ostreopsis sp. 6 grew in the temperature range 20–32.5 °C, whereas the strain of Ostreopsis sp. 7 grew in 20–30 °C. The semi-optimal temperature ranges (≧80% of the maximal growth rate) for the former three strains were 22.7–27.4 °C, 27.9–30.8 °C and 23.5–26.4 °C, respectively, whereas that of the latter strain was 23–27.2 °C. The optimal temperature for the O. cf. ovata South China Sea subclade was 30 °C, whereas for the others it was 25 °C. All the Ostreopsis strains tested could grow in a salinity range of 20–40. The semi-optimal salinities for the O. cf. ovata Thailand subclade, O. cf. ovata South China Sea subclade Ostreopsis sp. 6 and Ostreopsis sp. 7 were 28.7–35, 23.8–30.8, 29.8–36 and 28–36, respectively. The optimal salinities for the O. cf. ovata Thailand subclade and O. cf. ovata South China Sea subclade were 30 and 25, respectively, whereas for Ostreopsis sp. 6 and Ostreopsis sp. 7 it was 35. In this study, our results suggested that the optimal and tolerable temperature–salinity conditions differ among the Thai Ostreopsis species/clades/subclades. Tolerances of the O. cf. ovata Thailand subclade, O. cf. ovata South China Sea subclade and Ostreopsis sp. 6 to the high temperature of 32.5 °C may allow these organisms to be distributed in the tropical areas, where the water temperature often reaches >30 °C.
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- 2015
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9. Characterization ofGambierdiscusandCoolia(Dinophyceae) isolates from Thailand based on morphology and phylogeny
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Shinya Sato, Masao Adachi, Wittaya Tawong, Hiroshi Sakanari, Haruo Yamaguchi, and Tomohiro Nishimura
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Morphology (linguistics) ,Phylogenetic tree ,biology ,Plant Science ,Gambierdiscus ,Aquatic Science ,biology.organism_classification ,Agricultural and Biological Sciences (miscellaneous) ,Genus ,Phylogenetics ,Botany ,Clade ,Ciguatera fish poisoning ,Dinophyceae - Abstract
Summary The benthic dinoflagellates in the genus Gambierdiscus produce toxins that bioaccumulate in tropical and sub-tropical fish causing ciguatera fish poisoning (CFP). Other co-occurring genera such as Coolia have also been implicated in causing CFP. Little is known about the diversity of the two genera Gambierdiscus and Coolia along the Thai coasts. The results of morphological analyses based on observation under light microscopy and scanning electron microcopy showed that strains of Gambierdiscus from Thailand displayed the typical Gambierdiscus plate formula: Po, 4′, 0a, 6″, 6c,?s, 5′′′, 0p and 2′′′′. Morphological examination of Thai Gambierdiscus enabled it to be identified as Gambierdiscus caribaeus: round and anterior-posteriorly compressed cell shape, broad 2′′′′ plate, rectangular 2′ plate, and symmetrical 3″ plate. The phylogenetic analyses based on the large subunit (LSU) rDNA D8/D10 sequences of Gambierdiscus from Thailand confirmed the morphological identification. The thecal plate formula for all of the Coolia isolates from Thailand was Po, 4′, 0a, 6″,?c,?s, 5′′′, 0p and 2′′′′. Most, but not all, of these isolates could be identified morphologically as Coolia malayensis. An LSU rDNA D1/D2 phylogenetic analysis confirmed identity of C. malayensis isolates identified morphologically. The remaining unidentified isolates fell in the C. tropicalis clade.
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- 2014
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10. Distribution and molecular phylogeny of the dinoflagellate genus Ostreopsis in Thailand
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Masao Adachi, Wittaya Tawong, Haruo Yamaguchi, Tomohiro Nishimura, Shinya Sato, and Hiroshi Sakanari
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Dinoflagellate ,Subclade ,Plant Science ,Aquatic Science ,Biology ,biology.organism_classification ,Type species ,chemistry.chemical_compound ,Genetic distance ,chemistry ,Genus ,Palytoxin ,parasitic diseases ,Molecular phylogenetics ,Botany ,Ribosomal DNA - Abstract
The toxic benthic dinoflagellate genus Ostreopsis has been connected to the production of palytoxin and its analogs in many tropical and temperate areas. Although the type species, O. siamensis, was originally described from the Gulf of Thailand in 1901, little is known about the species composition and distribution of the genus Ostreopsis in Thailand. In this study, a total of 64 Ostreopsis strains isolated from the Andaman Sea as well as the Gulf of Thailand were investigated by analyzing the nucleotide sequences of the LSU rDNA D1/D2, D8/D10 and ITS-5.8S rDNA regions. Phylogenetic analyses (BI and ML) resulted in some of the strains being assigned to previously described clades, O. cf. ovata and Ostreopsis sp. 6, and revealed the existence of a novel clade named Ostreopsis sp. 7, which exhibited large genetic distances from the other clades. Among O. cf. ovata, several strains from Thailand were formed into a new subclade, the Thailand subclade, whereas a few strains belonged to the South China Sea subclade. Morphometric characteristics such as the cell sizes of the two O. cf. ovata subclades and those of Ostreopsis sp. 7 were not significantly different from each other (p > 0.05). Their characteristics were similar but slightly different from those of O. ovata and were significantly different from those of Ostreopsis sp. 6 (p < 0.05). Toxicities of Ostreopsis from Thailand were evaluated using mouse bioassay. Strains of Ostreopsis sp. 6 and Ostreopsis sp. 7 tested were highly toxic, while the two subclades of O. cf. ovata strains seemed to be nontoxic. This study suggests that toxic Ostreopsis sp. 7 is distributed in the Andaman Sea, whereas the two subclades of O. cf. ovata and toxic Ostreopsis sp. 6 are distributed in the Gulf of Thailand.
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- 2014
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11. Morphology of Gambierdiscus scabrosus sp. nov. (Gonyaulacales): a new epiphytic toxic dinoflagellate from coastal areas of Japan
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Masao Adachi, Haruo Yamaguchi, Shinya Sato, Wittaya Tawong, Hiroshi Sakanari, and Tomohiro Nishimura
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Rocky shore ,biology ,Gambierdiscus scabrosus ,Botany ,Dinoflagellate ,Plant Science ,Epiphyte ,Gambierdiscus ,Aquatic Science ,biology.organism_classification ,Cell shape ,Gonyaulacales - Abstract
A new epiphytic dinoflagellate is described, G ambierdiscus scabrosus sp. nov., from tidal pools and rocky shores along the coastal areas of Japan. Cells are 63.2 ± 5.7 μm in depth, 58.2 ± 5.7 μm in width, and 37.3 ± 3.5 μm in length. The plate formula of G . scabrosus is Po, 4', 0a, 6'', 6c, ?s, 5''', 0p, and 2''''. Morphologically, G . scabrosus resembles G . belizeanus as follows: anterioposteriorly compressed cell shape, narrow 2'''' plate, and areolated surface. Despite this similarity, the cells of G . scabrosus can be distinguishable by the presence of the asymmetric shaped 3'' plate and the rectangular shaped 2' plate.
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- 2013
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