Search Results (6)

Temporary wetlands are ecosystems formed by seasonal or intermittent inundation that provide habitats and support hydrological and biogeochemical processes. Despite their importance, they are often overlooked due to their small size and ephemeral nature. The lava forest of Jeju Island, known as Gotjawal, is a rare ecosystem where temporary wetlands occur despite the high permeability of basaltic terrain. This study reports an assessment of temporary wetlands in the Seonheul Gotjawal forest, focusing on identification, boundary delineation, and key characteristics. Wetlands were identified using four years (2020–2023) of water level monitoring and vegetation surveys. Hydrological boundaries were defined by maximum observed water levels, and ecological boundaries were delineated from plant distribution. Ecological boundaries consistently fell within hydrological ones, showing the value of vegetation indicators in wetland identification. Wetland areas ranged from 347–1214 m², with average depths of 0.2–0.9 m and hydroperiods of 13–76%. Water levels correlated with total rainfall. Three geomorphological wetland types were distinguished, with the shortest hydroperiods observed in small lava depressions functioning as forest microhabitats for endemic species. This study provides the first integrated evaluation of temporary wetlands in the Gotjawal lava forest and offers baseline data for classification and conservation. Full article

In our previous study, Lentzea sp. JNUCC 0626 was isolated from Hwasun Gotjawal on Jeju Island, and its melanogenic effects were confirmed in B16F10 melanoma cells through the identification of 1-acetyl-β-carboline. In this study, we conducted a comprehensive taxonomic characterization of Lentzea sp. JNUCC 0626, including enzymatic activities, carbohydrate metabolism, growth conditions, and cellular composition. Major fatty acids identified were iso-C16:0, iso-C15:0, and C15:0 anteiso, with polar lipids such as diphosphatidylglycerol, phosphatidylethanolamine, and several unidentified lipids. Ubiquinone Q-9 was determined as the predominant respiratory quinone. Enzymatic activity analysis (API ZYM) showed alkaline phosphatase, esterase (C4), esterase lipase (C8), and leucine arylamidase activities, while carbohydrate metabolism analysis (API 50CHB) indicated acid production from esculin alone. Complete genome sequencing revealed a 10,602,950 bp linear chromosome and a 177,940 bp plasmid. This plasmid encodes essential plasmid-related genes, including a Type IV secretion system and ParA proteins critical for plasmid transfer and stability. These findings suggest that the plasmid in Lentzea sp. JNUCC 0626 could be utilized for developing host–vector systems to facilitate the combinatorial biosynthesis of novel bioactive compounds. Comparative genomic analysis identified Lentzea pudingi CGMCC 4.7319 as the closest relative, but significant genetic divergence (dDDH 46.7%, ANI 88.02%) strongly supports the classification of Lentzea sp. JNUCC 0626 as a novel species. AntiSMASH analysis revealed 34 biosynthetic gene clusters (BGCs), highlighting the strain’s capacity to produce diverse bioactive compounds. Finally, the JNUCC 0626 extract exhibited concentration-dependent NO inhibition in LPS-stimulated RAW 264.7 cells, demonstrating significant anti-inflammatory activity. This suggests that the secondary metabolites inferred from genomic analysis may contribute to these observed bioactivities. Full article

A novel Bacillus subtilis HB-31 strain was isolated from Gotjawal Wetland in Jeju Island, Republic of Korea. A mucus substance produced by this strain was identified as high-molecular-weight poly-γ-glutamic acid (γ-PGA) using NMR, Fourier transform infrared spectroscopy, and size-exclusion chromatography/multi-angle light scattering analyses. We evaluated whether γ-PGA strengthened the skin barrier using keratinocytes and a reconstructed skin model. In keratinocytes, γ-PGA treatment dose-dependently increased the mRNA expression of skin barrier markers, including filaggrin, involucrin, loricrin, serine palmitoyl transferase, fatty acid synthase, and 3-hydroxy-3-methylglutaryl coenzyme A reductase. γ-PGA also enhanced hyaluronic acid synthesis by upregulating hyaluronic acid synthase-1, -2, and -3 mRNA levels and promoted aquaporin 3 expression, which is involved in skin hydration. In the reconstructed skin model, topical application of 1% γ-PGA elevated filaggrin, involucrin, CD44, and aquaporin 3 expression, compared to the control. These results suggest that the newly isolated HB-31 can be used as a commercial production system of high-molecular-weight γ-PGA, which can serve as an effective ingredient for strengthening the skin barrier and improving moisture retention. Further research is needed to explore the long-term effects of γ-PGA on skin health and its application in treating skin conditions. Full article

The genus Lentzea is a prolific source of bioactive and structurally diverse secondary metabolites. We isolated a novel strain, Lentzea sp. JNUCC 0626, from Hwasun Gotjawal on Jeju Island, Korea. Based on 16S rRNA partial gene sequence analysis, strain JNUCC 0626 is closely related to Lentzea isolaginshaensis NX62 (99.41% similarity), Lentzea pudingi DHS C021 (99.31%), and Lentzea cavernae SYSU K10001 (99.26%). From the fermentation broth of JNUCC 0626, we isolated 1-acetyl-β-carboline, whose structure was established using IR, HR-ESI-MS, and 1D- and 2D-NMR techniques. 1-acetyl-β-carboline was found to activate melanogenesis in mouse B16F10 cells without cytotoxicity at concentrations up to 50 μM. At this concentration, the compound increased melanin content by 27.44% and tyrosinase activity by 240.64% compared to the control, by upregulating key melanogenic enzymes, including tyrosinase, TRP-1, TRP-2, and microphthalmia-associated transcription factor (MITF), a central regulator of melanogenesis. In addition, 1-acetyl-β-carboline significantly inhibited ERK phosphorylation, reducing it by 20.79% at a concentration of 12.5 μM and by 25.63% at 25 μM. This inhibition supports the hypothesis that 1-acetyl-β-carboline enhances melanin synthesis by upregulating MITF and melanogenic enzymes via the ERK signaling pathway. This study aimed to isolate and identify 1-acetyl-β-carboline from a novel strain of Lentzea sp. JNUCC 0626, discovered in Gotjawal, Jeju Island, and to evaluate its effect on melanin production in B16F10 melanoma cells. Skin irritation tests on 32 subjects confirmed its safety for topical use, and the findings suggest that 1-acetyl-β-carboline, which enhances melanogenesis without cytotoxicity, holds promise as a therapeutic agent for hypopigmentation-related conditions or as a cosmetic ingredient. Full article

According to our research findings, the future-oriented conservation of natural ecological resources in the Sahn-Yang Gotjawal area should be shaped and formed in a sustainable ecological way to improve the economy of the Sahn-Yang area. This study covers a systematic and quantitative assessment of the function, design, and purpose of establishing a regional eco-tourism program using the Sahn-Yang Gotjawal (Volcanic Lava Stony Forest) natural resources of Jeju Island, South Korea. Although citizens’ interest in Jeju Gotjawal has increased, reckless exploration and damage still occurred. There were improvements on the movement to preserve geological features and the ecosystem. However, unfortunately the negative effects of only seeking development opportunities without regard to the environment was realized as well. Through strengths, opportunities, aspirations, results (SOAR) analysis, various potential situations and conditions using the Sahn-Yang Gotjawal resources were analyzed with quantitative and qualitative techniques. In addition, through media analysis, the benefits and opportunities that the Gotjawal resources could provide the citizens were identified and the results were combined with SOAR analysis to present an integrated vision. In order to make wise use of Sahn-Yang Gotjawal, such as conserving, sustaining, and creating accessibility (guided by SESs), it is necessary to concentrate on the ‘strengths’ such as creating and maximizing attractions which can develop management programs such as preservation research and monitoring, as well as establishing sustainable usage of facilities such as visitors’ gathering spaces, exploration activities, and convenient facilities. Full article

Knowledge about carbon and nutrient fluxes by litterfall is important for understanding nutrient cycling in geologically unique ecosystems. However, the determination of forest litterfall production patterns is difficult due to many biophysical factors influencing the process. In this study, we (1) quantified the litterfall production and carbon and nutrient fluxes in warm-temperate evergreen forest stands in Jeju Gotjawal and (2) compared these values to those of a typical cool-temperate deciduous forest stand by forest types and climate differences. Litterfall from evergreen broadleaved forests at Cheongsu (CS) and Seonheul (SH_b), a mixed forest at Seonheul (SH_m) in Jeju Gotjawal, and a deciduous broadleaved forest at Chungnam National University Forest (CNU) was collected for a full two years using litter traps. Samples were sorted into leaves, twigs, barks, seeds, and unidentified materials, and then weighed and measured for C, N, P, K, Ca, and Mg fluxes by litterfall. Results showed that the mean annual litterfall (846.3 g m⁻², average of CS, SH_b, and SH_m) at Jeju Gotjawal was similar to that of CNU (885.5 g m⁻²), but varied by site in Jeju Gotjawal: CS (933.1 g m⁻²) was significantly higher than the average of SH_b and SH_m (802.9 g m⁻²). Seasonal patterns of litterfall production differed by forest types; evergreen broadleaved forests showed a bimodal peak in fall and spring while deciduous broadleaved forests showed a unimodal peak in fall. Jeju Gotjawal had significantly higher total macronutrient concentrations and contents (except for K) than CNU and they also varied by site in Jeju Gotjawal: CS had higher N, P, Ca, and Mg contents than SH_b and SH_m. We conclude that litterfall production and nutrient fluxes differed by forest stand as influenced by forest types and climate. Further, our findings are important for understanding carbon and nutrient dynamics in the geologically unique ecosystem of Jeju Gotjawal and other areas with similar characteristics. Full article