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CO2 flux measurements and soil gas samples were collected to determine the origin and distribution characteristics of soil gas discharged at Andeok area, Jeju, South Korea. Additionally, this study aims to discuss agricultural activities that may contribute to increased soil CO2 emissions. CO2 flux was measured at 127 points, while soil gas sampling for gas components and carbon-13 (δ13CCO2) analysis was performed at 56 points. The measured CO2 fluxes in the study area ranged from 0.8 to 83.8 g/m2/d (mean: 14.3 g/m2/d), which was lower than CO2 fluxes observed in areas with geogenic CO2 discharge (e.g., near active volcanoes, faults, and CO2-rich water sources). The soil gas analysis revealed that the CO2 concentration and δ13CCO2 ranged from 491 to 23,722 ppmv (mean: 3,205 ppmv) and from −25.2 to −10.7‰ (mean: −19.4‰), respectively. In the cumulative probability diagram, the threshold values for CO2 flux and soil CO2 concentration were 41.3 g/m2/d and 6,693 ppmv, respectively. Samples exceeding the CO2 flux threshold were affected by urea fertilizer application based on land use nearby, and did not overlay with samples exceeding the soil CO2 threshold, indicating different transport mechanisms. Results from a detailed survey near a soil gas sampling location close to high soil CO2 showed that soil CO2 concentrations increased with depth, especially during summer when atmospheric temperatures increased. Spatially, higher soil CO2 concentrations were observed in areas with accumulated plant debris from tangerine orchards. The δ13CCO2 and relationships among CO2-O2, N2-CO2, and N2/O2-CO2 indicated that all collected samples had a biogenic origin. Although geogenic soil gases were not observed in this study, our findings are useful for future research on Jeju Island, as they provide baseline values for distinguishing geogenic soil gas from those with natural and agricultural origins. Moreover, this result provides insights into agricultural activities such as urea fertilization and plowing and their contribution to soil CO2 increase, and inspires future research on negative soil CO2 flux. [ABSTRACT FROM AUTHOR]

Cathepsin L of cancer cells has been shown to play an important role in degradation of extracellular matrix for metastasis. In order to reduce cell invasion, cathepsin L propeptide-like proteins which are classified as the I29 family in the MEROPS peptidase database were characterized from Calotropis procera R. Br., rich in cysteine protease. Of 19 candidates, the cloned and expressed recombinant SnuCalCp03-propeptide (rSnuCalCp03-propeptide) showed a low nanomolar Ki value of 2.3 ± 0.2 nM against cathepsin L. A significant inhibition of tumor cell invasion was observed with H1975, HT29, MDA-BM-231, PANC1, and PC3 with a 76, 67, 67, 63, and 79% reduction, respectively, in invasion observed in the presence of 400 nM of the rSnuCalCp03-propeptide. In addition, thermal and pH study showed rSnuCalCp03-propeptide consisting of secondary structures was stable at a broad range of temperatures (30-70 °C) and pH (2-10, except for 5 which is close to the isoelectric point of 5.2). [ABSTRACT FROM AUTHOR]

Food spoilage caused by yeast is a common problem in the food industry, and has led to the use of chemical preservatives. However, chemicals have not been widely accepted by consumers in recent years due to their perceived adverse effects on health. Therefore, plant-derived ingredients and additives have been attracting interest as potential alternatives. Our research group previously reported novel α-helical propeptides (SnuCalCpIs) derived from the medicinal plant Calotropis procera R. Br, as potential candidates for antimicrobial preservatives. In the present study, their activity against four food spoilage yeasts was investigated. The antimicrobial peptide, SnuCalCpI15, exhibited minimum inhibitory activity of 0.20 ± 0.01, 0.20 ± 0.01, 0.26 ± 0.01, and 0.26 ± 0.01 mM against Candida albicans , Saccharomyces cerevisiae, Pichia anomala , and Rhodotorula mucilaginosa , respectively. Fluorescein isothiocyanate (FITC) labeling revealed that SnuCalCpI15 initially bound to yeast cell surfaces and then entered the cells. Increased cell membrane permeability was determined based on the LIVE/DEAD cell viability assay and propidium iodide (PI) uptake. Morphological changes in yeast cells, especially altered cell wall thickness, were investigated using transmission electron microscopy (TEM). The results indicated that SnuCalCpI15 is a potent alternative to chemical antifungal food preservatives, and can be used to improve the shelf life and quality of foods vulnerable to yeast spoilage. • Antifungal activity of α-helical propeptides (SnuCalCpIs) was investigated. • Among SnuCalCpIs, only SnuCalCpI15 exhibited antifungal activity against food spoilage yeasts. • Cell membrane permeability of SnuCalCpI15 was facilitated by clearly segregated polar and apolar residues. • It can be used to improve the shelf life and quality of foods vulnerable to yeast spoilage. [ABSTRACT FROM AUTHOR]

A mixture of basaltic fragments and sediments within a basalt, formely interpreted as a peperite in Korea, shows a difference from the typical peperite features at the boundaries between two rocks. As a result of SEM-EDS analysis, there is no evidence of glassy rim along the margin of the basalt fragments and disturbance in the sediments composed of quartz and clay minerals. These textures are not consistent with a typical feature of the peperite that the internal sedimentary structures are destroyed by fluidization of the host sediment and glassy rim is formed along the margin of clasts of magma origin. On the other hand, the characteristics of the basalt fragments with uneven margins and basalt fragments in the sediments are interpreted that the fluid injected inside crushed the basalt in place and grown and filled the gap with quartz that was carrying it. The sediments within the basalt, therefore, envisaged the veins produced by the secondary fluid. These results represent that the peperitic texture is pesudo-peperite produced by secondary hydrofracture, rather than the synsedimentary volcanism. [ABSTRACT FROM AUTHOR]