From 2017 to 2024, we surveyed 43 diverse aquatic habitats in South Korea, leading to the identification of 18 cyanobacterial taxa that are newly recorded for the country, found across eight sites (about 18% of the surveyed locations). These taxa exhibit a wide range of morphological forms, including unicellular, colonial, filamentous, and heterocytous types, and belong to various orders such as Chroococcales, Synechococcales, Nostocales, and Stigonematales. Notably, this study provides a provisional record of Gomphosphaeria aponina in Korea, correcting its previous misidentification as G. natans. We also documented Dolichospermum compactum, a species that has been genetically reclassified. Additionally, we identified species with the potential to cause harmful algal blooms (HABs), such as Microcystis botrys and Gloeotrichia aurantiaca, which are crucial for domestic water quality monitoring. Currently, only 414 cyanobacterial taxa are recorded in Korea, representing less than 8% of the estimated global total of approximately 5,300 species. This significant gap underscores the considerable unrecorded diversity within Korean aquatic ecosystems. These findings substantially enhance the national cyanobacterial checklist and underscore the need for ongoing monitoring in understudied aquatic environments. They also highlight the importance of integrating classical morphological and ecological observations with advanced molecular methods. This polyphasic approach can accurately detect cryptic diversity and support robust ecological assessments. Overall, this comprehensive floristic expansion offers valuable baseline data for biodiversity inventories, ecological monitoring, and the development of microbial resources within Korean aquatic environments.

The genus Pleurastrum is a coccoid green alga comprising 10 species worldwide. Pleurastrum exhibits simple morphology and high polymorphism, which complicates the understanding of its diversity. We examined the morphological and ultrastructural characteristics of Pleurastrum using light, confocal, and transmission electron microscopy. Additionally, we performed phylogenetic analysis based on multigene sequences (nuclear SSU rDNA, 5.8S, internal transcribed spacer (ITS2) region, and plastid rbcL and tufA genes) from Pleurastrum strains to report two previously unrecorded freshwater species (Pleurastrum insigne and Pleurastrum microstigmatum) in Korea. The vegetative cells were predominantly spherical, with a few being ellipsoidal, and each cell contained a chloroplast with one pyrenoid. The sporangia produced several daughter cells, while the biflagellate zoospores were ellipsoidal and motile. Phylogenetic analysis confirmed that P. insigne and P. microstigmatum form well-supported monophyletic clades. Analysis of ITS2 secondary structures revealed similar patterns, with several differences in nucleotide sequences and insertions between the two species. The findings of this study expand the known distribution of Pleurastrum and enhance our understanding of its species diversity in Korea.

Desmidiales (Conjugatophyceae, Charophyta) are commonly found in freshwater ecosystems and exhibit high species diversity, particularly in acidic wetlands, lakes, swamps, and peat bogs. They possess a distinctive morphology characterized by symmetrical semicells, and their wide variation in cell shape and size presents challenges in species identification due to high morphological plasticity. Although 832 species of Desmidiales have been reported in Korea, phylogenetic studies have been limited to only a few taxonomic groups. This study focused on investigating species-level relationships among Desmidiales using strains from the Freshwater Bioresources Culture Collection (FBCC), integrating morphological characteristics, ecological data, and original species descriptions. A total of 352 new plastid gene sequences were generated for phylogenetic analyses, including accD (30), atpA (42), atpB (22), ndhH (37), petA (37), psaA (32), psbA (44), psbC (1), psbD (39), rbcL (40), rpl2 (19), and rpoB (9). Among the 12 plastid genes analyzed, psbA showed the highest proportion of conserved sites (83.9%), while petA exhibited the highest proportion of variable sites (38.7%). Based on the combined phylogenetic analysis, Desmidiales were grouped into five major clades: Cosmarium Clade-1: Cosmarium punctulatum, Cosmarium sp. 1, Cosmarium Clade-2: C. blyttii, C. botrytis, C. costatum, C. ochthodes, C. pachydermum, C. subcostatum, C. subcrenatum, C. subprotumidum, C. trilobulatum, Cosmarium Clade-3: C. angulosum, C. formosulum, C. granatum, C. impressulum, C. norimbergense, C. regnellii, C. subtumidum, Cosmarium sp. 2, Staurastrum Clade-1: Staurastrum avicula var. lunatum, Staurastrum Clade-2: S. boreale, S. dispar, S. kouwetsii, S. margaritaceum, S. punctulatum. The newly generated sequence data from FBCC strains will serve as a valuable resource for accurate species identification and for exploring the molecular ecology of Desmidiales in freshwater ecosystems. This phylogenetic framework improves our understanding of Desmidiales species diversity in Korea and aids in achieving a more comprehensive taxonomic resolution within this algal order.

The objective of this study was to assess the effects of gypsum application on dry matter yield (DMY), mineral content of alfalfa (Medicago sativa L.), and soil properties in reclaimed tidal land in South Korea. The experiment was conducted in Seokmun, located on the west coast of South Korea, which is reclaimed with approximately 70 cm depth of degraded island soil. Treatments consisted of a control with no gypsum application (G0), 2 ton ha-1 (G2), and 4 ton ha-1 (G4) of gypsum application. The first harvest was carried out when the alfalfa reached 10% flowering, and subsequent harvests were conducted at 35-day intervals. Over the three-year experimental periods (2019-2021), the total DMY of G2 treatment was significantly higher than those of G0 and G4 (p<0.05). Although both G2 and G4 gypsum application treatments lowered soil pH, the G4 treatment increased the electrical conductivity (EC) content of the soil. Additionally, gypsum application affected the mineral contents of alfalfa, resulting in reduced concentration of sodium (Na) and Magnesium (Mg). Therefore, this present study suggests that a gypsum application rate of 2 ton ha-1 is optimal for improving alfalfa dry matter yield and mineral balance, as well as enhancing soil chemical properties in reclaimed tidal land in South Korea.

Background: Dairy cows exposed to heat stress have reduced milk production, milk quality, and conception rates, leading to lower profits. This study was conducted to analyze the effect of heat stress according to Temperature-Humidity Index (THI) on the milk production of Korean Holstein cows. Methods: Monthly maximum temperature and average relative humidity data from January 2017 to August 2024 were obtained from 62 observation points used by the Korea Meteorological Administration to calculate the national average. Using this data, the THI, a key indicator for assessing heat stress in Korean Holstein cows, was calculated. Additionally, data from 240,088 Korean Holstein cows, collected through tests conducted by the Dairy Cattle Improvement Center of the NH-Agri Business Group, were analyzed. Results: Comparative analysis of the relationship between THI and milk production revealed that milk yield remained relatively stable until THI reached the “very severe” heat stress threshold (THI ≥ 79). Beyond this level, milk production showed a tendency to decline. Conversely, when THI dropped below this threshold, milk yield tended to recover. Notably, the temperature in September, typically considered part of the autumn season, has been rising in recent years, with THI values now approaching the very severe stress level (THI ≥ 79). Conclusions: These findings suggest that establishing an appropriate farm environment and implementing systematic THI management are essential for mitigating the decline in milk production, as well as the associated economic losses, caused by rising domestic temperatures due to global warming.

Human dermal fibroblasts (HDFs) play a critical role in maintaining skin integrity and promoting tissue repair, but are highly susceptible to apoptosis under stress conditions such as nutrient deprivation. Adipose-derived stem cells (ADSCs) have emerged as a promising therapeutic option due to their regenerative potential and ability to secrete bioactive factors. In this study, we investigated the effect of ADSC-derived paracrine signaling on apoptosis in HDFs and explored the underlying molecular mechanisms. Using a Transwell co-culture system, we found that ADSCs significantly reduced apoptosis in HDFs subjected to low-serum stress, as confirmed by APOPercentage™ staining and the expression of apoptosis-related proteins. Among several soluble factors secreted by ADSCs, hepatocyte growth factor (HGF) exhibited the most pronounced time-dependent increase in culture supernatants. The anti- apoptotic effect of ADSCs was abolished by neutralizing antibodies against HGF, indicating a key role of this factor in mediating fibroblast survival. Further, HDFs were found to express the HGF receptor c-Met at both the mRNA and protein levels. Inhibition of c-Met signaling reversed the cytoprotective effect of ADSCs, suggesting that HGF functions through this receptor. Mechanistically, only the PI3K/AKT pathway—among the major survival pathways tested—was selectively activated in HDFs by ADSC co-culture. Pharmacological inhibition of PI3K/AKT signaling using LY294002 abolished the protective effect, while inhibition of ERK or p38 MAPK had no significant impact. These findings demonstrate that ADSC-derived HGF protects HDFs from stress-induced apoptosis primarily through activation of the c-Met–PI3K/ AKT pathway. This mechanistic insight may provide a basis for the development of stem cell– based therapies aimed at enhancing skin regeneration and fibroblast viability in degenerative or wound-healing contexts.

In this study, proteins were extracted from sesame and perilla meals (agricultural by-products) by using hot-water defatting and acid precipitation, and their functional properties were compared with those of a commercial soy protein isolate (SPI). According to the SDS-PAGE results, the sesame meal protein extract (SMPE) exhibited a higher content of hydrophobic amino acids than the perilla meal protein extract (PMPE), alongside a relatively lower intensity of the 7S globulin band. SMPE showed 1.41-fold higher solubility than SPI at pH 10 and 1.72- and 1.66-fold higher emulsifying activity indices (EAIs) at pH 8 and 10, respectively. PMPE exhibited similar trends in solubility and EAI as SPI at the corresponding pH values. However, the emulsifying stability indices of SMPE and PMPE were lower than that of SPI. In particular, the fat absorption capacity of SMPE was significantly higher than those of SPI and PMPE, likely because of its higher content of hydrophobic or nonpolar amino acid residues. These results suggest that SMPE and PMPE are promising alternative protein sources for food applications and may promote value-added utilization of plant-derived by-products in the food industry.

In this study, conjugates were prepared via dry heat-induced glycosylation with maltodextrin (MD) to enhance the functional properties of sesame meal protein extract (SMPE). With the progress of conjugation, the specific protein bands of SMPE decreased and new bands appeared in the higher molecular weight range (approximately 170 kDa). The FT-IR spectra confirmed the structural modifications resulting from Maillard reaction-driven covalent bonding between SMPE and MD. The solubility and emulsifying properties—emulsifying activity index (EAI) and emulsifying stability index (ESI)—of the conjugates showed little variation with dry-heat treatment time, but they were significantly influenced by the dextrose equivalent (DE) of MD. Solubility was highest when SMPE was conjugated with MD of DE 4–7 at both 12 h (19.38%) and 24 h (20.54%) and decreased as DE increased. Notably, the three-way ANOVA results showed that the emulsifying properties improved significantly with higher DE of MD. The EAI and ESI of SMPE conjugated with MD of DE 16.5–19.5 increased by 1.52- and 1.41-fold, respectively, when compared with the control SMPE. These findings suggest that the SMPE-MD conjugates have promising potential for applications in food systems that require enhanced emulsifying properties.