This study reports seven new records of marine gastropod species from Korean waters: Marsenina uchidai, Littoraria sinensis, Conus litteratus, Pleurobranchus forskalii, Placida dendritica, Placida kevinleei, and Thuridilla lineolata. Notably, this marks the first documentation of the genus Marsenina in Korea. Specimens were collected from various locations along the Korean coast, including Goseong and Yangyang (Gangwon-do), Dokdo, Bito Island (Sacheon, Gyeongsangnam-do), and Jeju Island, between February 2025 and March 2026. Each species identification was based on diagnostic morphological characters and supported by photographs of living individuals or preserved specimens. Uncorrected p-distance analyses and maximum-likelihood (ML) phylogenetic reconstructions, using COI sequences, confirmed the taxonomic identities of the specimens. Among the species studied, Conus literatus and Placida dendritica showed significantly higher intraspecific genetic divergences compared to the other taxa, indicating a need for further taxonomic and population-level research. These findings enrich the existing inventory of marine gastropod biodiversity in Korean waters and offer foundational data for future taxonomic and biogeographic studies.

Polysaccharides possess various biological activities that can be applied in food, pharmaceutical, cosmeceutical, textile and paper industries. Although industrial polysaccharides are mainly produced by higher plant and seaweed, microorganisms are recognized as potential substitutes for the current major resources of polysaccharides due to their easy purification process and high production efficiency. In this study, we explored extracellular polysaccharides (EPS) produced by the fungus Gibellulopsis serrae strain JJ-W1 isolated from seawater. When cultured in media supplemented with three different carbon sources including glucose, maltose, and sucrose, the highest EPS production was observed in the glucose medium. In addition, the G. serrae EPSs showed inhibitory effects on collagenase activity. At a concentration of 20 mg/mL, collagenase activity was completely inhibited by the G. serrae EPSs, and the half-maximal inhibitory concentration(IC50) value was 6.21 ± 0.26 mg/mL. Based on the structural analysis of FT-IR spectra, the G. serrae EPSs exhibited different properties depending on the carbon sources. The EPSs produced in the glucose medium contained both α- and β-glycosidic linkages, whereas those from maltose or sucrose media contain only α-glycosidic bonds. Given the limited research on fungal polysaccharides and their collagenase inhibition, this study may provide basic information for their potential use in cosmetics.

Expanding dye use elevates ecological risks by increasing dye-contaminated wastewater discharge. Cationic dyes resist removal owing to high stability and toxicity, but activated carbon adsorption remains an efficient and economical treatment. In this study, we examine methylene blue (MB) removal using activated carbon prepared from petroleum pitch through KOH activation, followed by nitrogen plasma treatment for 5, 10, 15, and 30 min. To characterize the surface chemistry and porosity of the nitrogen-functionalized carbon, we employed elemental analysis (EA), X-ray photoelectron spectroscopy (XPS), and N2 adsorption–desorption (Brunauer-Emmett-Teller, BET) measurements. Batch adsorption tests were conducted at MB concentrations of 100, 200, 300, 400, and 500 mg L⁻¹. The nitrogen plasma treatment increased the surface nitrogen content (from 0.44% to 1.94% depending on the treatment conditions) and enhanced MB adsorption performance. Equilibrium data were fitted using the Langmuir and Freundlich isotherm models; the Freundlich model showed a better correlation, indicating multilayer adsorption on a heterogeneous surface and suggesting that plasmaintroduced nitrogen sites provided additional adsorption sites.