A5051804791- Microbial Community Ecology and Physiology
- Marine and coastal ecosystems
- Protist diversity and phylogeny
- Coral and Marine Ecosystems Studies
- Marine and coastal plant biology
- Marine Biology and Ecology Research
- Algal biology and biofuel production
- Marine Toxins and Detection Methods
- Aquatic Ecosystems and Phytoplankton Dynamics
- Microbial Natural Products and Biosynthesis
- Marine Sponges and Natural Products
- Biocrusts and Microbial Ecology
- Coastal wetland ecosystem dynamics
- Diatoms and Algae Research
- Carbohydrate Chemistry and Synthesis
- Environmental DNA in Biodiversity Studies
- Genomics and Phylogenetic Studies
- Aquaculture disease management and microbiota
- X-ray Diffraction in Crystallography
- Photosynthetic Processes and Mechanisms
- Lichen and fungal ecology
- Crystallization and Solubility Studies
- Pneumocystis jirovecii pneumonia detection and treatment
- Chemical synthesis and alkaloids
- Fish biology, ecology, and behavior
University of the Ryukyus
2014-2024
SRM University
2024
VIT-AP University
2024
Tokyo University of Science
1992-2023
University of the Ryukyus University Hospital
2012-2023
Keio University
2014
The University of Tokyo
2011
National Institute for Environmental Studies
2004
The marine epiphytic dinoflagellate genus Gambierdiscus produce toxins that cause ciguatera fish poisoning (CFP): one of the most significant seafood-borne illnesses associated with consumption worldwide. So far, occurrences CFP incidents in Japan have been mainly reported subtropical areas. A previous phylogeographic study Japanese revealed existence two distinct phylotypes: sp. type 1 from and 2 temperate However, details genetic diversity distribution for are still unclear, because a...
Genomic DNA homologies were examined from six Microcystis (cyanobacteria) strains, including five different species, aeruginosa, ichthyoblabe, novacekii, viridis and wesenbergii. All DNA-DNA reassociation values between two strains of M. aeruginosa the other four species exceeded 70%, which is considered high enough for them to be classified within same bacterial species. It proposed unify these into under Rules Bacteriological Code NIES843T (= IAM M-247T) as type strain. Two flos-aquae...
Serial observations were carried out on cultures of five morphospecies the genus Microcystis Kützing ex Lemmermann 1907, aeruginosa (Kützing) Kützing, ichthyoblabe novacekii (Komárek) Compére, viridis (A. Brown) Lemmermann, and wesenbergii Komárek in Kondratieva. Many strains maintained colony forms characteristic their morphospecies, others showed morphological variations, some which other morphospecies. M. displayed several morphotypes including characteristics ichthyoblabe. also great...
The subfamily Mastophoroideae (Corallinaceae, Rhodophyta) is characterized by species possessing nongeniculate, uniporate tetrasporangial conceptacles without apical plugs, the presence of cell fusions, and absence secondary pit connections. However, molecular phylogenetic studies not including type genus Mastophora indicated that was polyphyletic. Our analysis using DNA sequences SSU rDNA plastid-encoded gene PSII reaction center protein D1 (psbA) revealed formed a robust clade only with...
Background A dinoflagellate genus Ostreopsis is known as a potential producer of Palytoxin derivatives. the most potent non-proteinaceous compound reported so far. There has been growing number reports on palytoxin-like poisonings in southern areas Japan; however, distribution not investigated Morphological plasticity makes reliable microscopic identification difficult employment molecular tools was desirable. Methods/Principal Finding In total 223 clones were examined from samples mainly...
Rhodes L., Smith K., Selwood A., McNabb P., Munday R., Suda S., Molenaar S. and Hallegraeff G. 2011. Dinoflagellate Vulcanodinium rugosum identified as the causative organism of pinnatoxins in Australia, New Zealand Japan. Phycologia 50: 624–628. DOI: 10.2216/11-19.1The producers E F were first through systematic light microscopy-mass spectrometry (LC-MS) screening (NZ) dinoflagellate isolates. Pinnatoxins E, G subsequently detected for South Australian (AUS) isolates, a pinnatoxin producer...
In spite of their ecological importance as primary producers and microbioeroders marine calcium carbonate (CaCO3) substrata, endolithic phototrophs spanning both prokaryotic (the cyanobacteria) eukaryotic algae lack established molecular resources for facilitated survey with high throughput sequencing. Here, the development a metabarcoding framework elongation factor EF-Ttu (tufA) was tested on four Illumina-sequenced CaCO3 microfloras characterization phototrophs, especially abundant...
Endozoicomonas bacteria symbiosis with various marine organisms is hypothesized as a potential indicator of health in corals. Although many amplicon analyses using 16S rRNA gene have suggested the diversity species, genome analysis has been limited due to contamination host-derived sequences and difficulties culture metagenomic analysis. Therefore, evolutionary functional individual species symbiotic same coral remains unresolved. In this study, we applied novel single-cell genomics...
Kurahyne, a new acetylene-containing lipopeptide, was isolated from marine cyanobacterial assemblage that mostly consisted of <italic>Lyngbya</italic> sp. Kurahyne inhibited the growth human cancer cells and induced apoptosis in HeLa cells, it seemed to localize mitochondria.
Summary The nongeniculate species N eogoniolithon brassica‐florida ( H arvey) S etchell et M ason is circumscribed as a polymorphic with various gross morphologies due to it being synonymized several previous species. However, small subunit rDNA and cox 1 analyses showed that . was polyphyletic, strongly imply crustose lacking any protuberances such fosliei eydrich) or branches frutescens F oslie) should be treated genetically different groups (species). Therefore, we propose the...
On our quest for new bioactive molecules from marine sources, two cyclic imines (1, 2) were isolated a dinoflagellate extract, inhibiting the growth of respiratory syncytial virus (RSV). Compound 1 was identified as known molecule portimine, while 2 elucidated to be imine, named kabirimine. The absolute stereochemistry determined by crystallographic work and chiral derivatization, whereas structure means spectroscopic analysis computational study on all possible isomers. showed potent...
Ten strains of Nannochloropsis species in the Marine Biotechnology Institute Culture Collection (MBIC), Japan, were classified as N. granulata (one strain), salina gaditana (three strains) and oceanica Suda & Miyashita sp. nov. (five by determining nearly complete 18S rDNA sequences. The sequences belonging to same all identical. Rubisco (rbcL) gene 10 also determined. substitution frequencies among rbcL genes these four more than three times higher those rDNA, especially between salina,...
Abstract Kurahamide, a new dolastatin 13 analog, was isolated from marine cyanobacterial assemblage, consisting mostly of Lyngbya sp. Its gross structure elucidated by spectroscopic analysis, and the stereochemistries were assigned based on chiral HPLC analysis hydrolysis products. Kurahamide strongly inhibited elastase chymotrypsin in vitro. In addition, kurahamide moderately growth human cancer cells, including HeLa HL60 cells.
Abstract A new species of Nephroselmis, Nephroselmis anterostigmatica, is described from coastal waters the Palau Islands and southern part Japan. The long flagellum was stretched out at angle to cell showed a characteristic sigmoid line. cup-shaped yellowish green chloroplast with two narrow sinuses included pyrenoid tubular invaginations thylakoids. In contrast other eyespot located anterior side cell. transitional region possessed single plate stellate structure. body covered by types...
Minnamide A is a lipopeptide with unique repeating structure consisting of hydroxy and proposed β-branched methyl groups. The absolute configuration minnamide was determined by combination chemical degradation, chiral HPLC analyses, synthetic methods. showed growth-inhibitory activity toward HeLa cells an IC50 value 0.17 μM rapidly induced cell death at concentration 2 μM. the copper-mediated accumulation reactive oxygen species.
Carotenoid compositions were analyzed for ten strains of Nephroselmis (Prasinophyceae) containing four described and three undescribed species. Based on the distribution pattern siphonaxanthin series, five carotenoid types recognized in examined strains/species: type I ( N . astigmatica Inouye et Pienaar, N. pyriformis (N. Carter) Ettl, sp1. MBIC 11158) had C12:1 C14:1 esters as well 6′‐OH esters, II sp2. 11149) C8:1 ester, III sp3. NIES 486, NIES‐PS 535, 10871) 19‐methoxy IV spinosa Suda)...
We studied the taxonomy of Hafniomonas species (Chlorophyceae) by LM and EM DNA sequence analysis on eight culture strains, including six new isolates collected from various localities in Japan. The strains could be clearly delineated into five species, reticulata (Korshikov) H. Ettl et Moestrup, H . montana (Geitler) laevis Nakada, Suda Nozaki sp. nov., conica (H. Ettl) Nakada stat. turbinea based differences cell shape, size, chloroplast surface, number contractile vacuoles, stigma...
Terrestrial cyanobacteria are extremely diverse. In urban areas, they can be found as black stains on the surface of building walls, stone monuments, or man-made structures. Many terrestrial still understudied. To expand knowledge cyanobacterial diversity, a polyphasic characterization was performed to identify 12 strains isolated from campus University Ryukyus, Okinawa, Japan. Multigene phylogenetic analyses based 16S rRNA gene and 16S-23S internal transcribed spacer (ITS) region showed...
The evolutionary and population demographic history of marine red algae in East Asia is poorly understood. Here, we reconstructed the phylogeographies two upper intertidal species endemic to Asia, Gelidiophycus divaricatus G . freshwateri Phylogenetic phylogeographic inferences 393 mitochondrial cox 1, 128 plastid rbc L, 342 nuclear ITS 2 sequences were complemented with ecological niche models. , a southern adapted warm water, characterized by high genetic diversity strong geographical...