Quantification of Alexandrium catenella (Group I) using sxtA4-based digital PCR for screening of paralytic shellfish toxins in Jinhae-Masan Bay, Korea.

We employed a detection method to quantify Alexandrium catenella (Group I), one of the causative species for paralytic shellfish poisoning (PSP) in Jinhae-Masan Bay, Korea, targets sxtA4, via chip-based digital PCR. Additionally, we explored the dynamics of Alexandrium during the spring of 2022 using an rDNA-based quantitative PCR (qPCR) assay to enhance the performance of the dPCR assay. In matching dPCR results with PSP monitoring reports, we optimized a cell regulatory threshold of 102 cells L, the maximum cell density when shellfish harvesting was permitted, for the dPCR assay.

Metagenomic Analysis of the Species Composition and Seasonal Distribution of Marine Dinoflagellate Communities in Four Korean Coastal Regions.

Biomonitoring of dinoflagellate communities in marine ecosystems is essential for efficient water quality management and limiting ecosystem disturbances. Current identification and monitoring of toxic dinoflagellates, which cause harmful algal blooms, primarily involves light or scanning electron microscopy; however, these techniques are limited in their ability to monitor dinoflagellates and plankton, leaving an incomplete analysis. In this study, we analyzed the species composition and seasonal distribution of the dinoflagellate communities in four Korean coastal regions using 18S rRNA amplicon sequencing.

Voratins A-C: Pyridinium Alkaloids from the Marine Dinoflagellate with Inhibitory Effects on Biomarkers for Benign Prostatic Hyperplasia.

Three voratin compounds (-) were isolated from the symbiotic marine dinoflagellate . The planar structures of - were determined by 1D and 2D NMR spectroscopy and HRESIMS, and the relative and absolute configurations were established using ROESY correlations, Mosher's method, and quantum calculations. All of the compounds are zwitterionic and contain a dihydroindolizinium ring and a spiroketal moiety.

Ovataline: A Polyketide Isolated from the Benthic Dinoflagellate cf. with 5α-Reductase Inhibitory Activity in RWPE-1 Prostatic Cells.

Ovataline (), which is a polar metabolite containing a hexahydroquinoline moiety, was isolated from cultures of the marine dinoflagellate cf. . was characterized as a zwitterionic compound with hexahydroquinoline and tetrahydropyran rings.

Development of a Method for Detecting Based on the Quantification of by Chip-Based Digital PCR.

which produces the paralytic shellfish toxin (PST) saxitoxin (STX), is one of the causative species of paralytic shellfish poisoning outbreaks in coastal areas of Korea. In this study, we developed a chip-based digital PCR (dPCR) method for detection and tested it for monitoring in Jinhae-Masan Bay. Using the sequence of an strain isolated in 2017, species-specific primers targeting (a STX biosynthesis-related gene) were designed and used in a dPCR, detecting 2.

sp. nov. (Chlorodendrophyceae), a Euryhaline Microalga Found in Supralittoral Tide Pools at Jeju Island, Korea.

We found the euryhaline microalga, sp. nov., which was adapted to supralittoral tide pools with salinities varying from 0.

Characterization of a New Trioxilin and a Sulfoquinovosyl Diacylglycerol with Anti-Inflammatory Properties from the Dinoflagellate Oxyrrhis marina.

Two new compounds-a trioxilin and a sulfoquinovosyl diacylglycerol (SQDG)-were isolated from the methanolic extract of the heterotrophic dinoflagellate cultivated by feeding on dried yeasts. The trioxilin was identified as (4,8,13,16,19) -7(),10(),11()-trihydroxydocosapentaenoic acid (), and the SQDG was identified as (2)-1--hexadecanosy-2--docosahexaenoyl-3--(6-sulfo-α-d-quinovopyranosyl)-glycerol () by a combination of nuclear magnetic resonance (NMR) spectra, mass analyses, and chemical reactions. The two compounds were associated with docosahexaenoic acid, which is a major component of .

Vitrification of immature bovine oocytes by the microdrop method.

This study was conducted to determine the optimal vitrification conditions for immature bovine oocytes using the microdrop method. In experiment 1, the optimal pre-equilibration period for microdrop vitrification was examined. The maturation rate of vitrified oocytes with a 3 min first pre-equilibration period (41.