During an investigation of indigenous prokaryotic species in the Republic of Korea, 17 bacterial strains belonging to the phylum Bacteroidota and 4 strains belonging to the phylum Bacillota were isolated from freshwater environments. These isolated bacterial strains formed a robust phylogenetic clade with type strains of the closest related bacterial species, with 16S rRNA gene sequences sharing similarities of higher than 98.7%. To date, there have been no official report of these 21 isolates in the Republic of Korea. At the genus level, these unreported species were affiliated with Mucilaginibacter and Pedobacter of class Sphingobacteriia, Flavobacterium and Gillisia of class Flavobacteriia, Hymenobacter of class Cytophagia, and Paenibacillus and Planococcus of class Bacilli. These species were further examined by performing Gram staining, analyzing their colonies and cell morphologies, and determining their basic biochemical characteristics and phylogenetic positions. Detailed descriptions of the 21 previously unreported species are provided.
Freshwater environments serve as crucial habitats for diverse microorganisms, playing essential roles alongside plants and animals within the ecosystem. Bacteria in these environments are particularly important for maintaining ecosystem functions. Among them, members of the phylum Pseudomonadota are known to be involved in processes such as nitrogen fixation, ammonia oxidation, and biofilm formation. Pseudomonadota comprises six classes: Acidithiobacillia, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Hydrogenophilia, and Zetaproteobacteria. This study reports 43 previously unrecorded species belonging to the phylum Pseudomonadota. They were isolated from various freshwater habitats in Republic of Korea. These strains were isolated and cultured using nine different standard media, with classification based on Gram staining, cell morphology, and biochemical characteristics. Species identity was determined using 16S rRNA gene sequencing, with a similarity threshold of 98.7% for designation as unreported species. Phylogenetic analysis revealed that these 43 strains were distributed across three classes, 13 orders, 28 families, and 39 genera. This research emphasizes microbial diversity in freshwater ecosystems and provides valuable insights into ecological roles and potential novel functions of unreported bacterial species in Korea.
The first African swine fever (ASF) virus infection in wild boar was reported in October in 2019 in Yeoncheon-gun. ASF control measures including passive/active surveillance, fencing, or hunting have been applied by the Korean government from the beginning of disease outbreak. Despite significant financial investment in ASF control strategies, the virus has continued to circulate among wild boars up to 2024. A basic reproduction number (R0) can be used to evaluate the effectiveness of ASF control strategy by providing the disease spread speed. During the ASF epidemic period, the spread speed could be estimated with the average number of new cases generated by an infected case. The current study estimated R0 for the 2019/24 ASF epidemics in wild boars in the Republic of Korea by using the daily reported number of ASF cases and the serial interval of ASF virus. The estimated mean R0 was 2.19 (range: 0.03 - 65.00) for the 2019/24 ASF epidemics, 3.05 (range: 0.70 - 10.40) in 2019, 2.01 (range: 0.06 - 9.79) in 2020, 1.94 (range: 0.07 - 7.35) in 2021, 4.71 (range: 0.21 - 61.95) in 2022, 1.93 (range: 0.11 - 7.53) in 2023, and 3.08 (range: 0.09 - 24.59) in 2024, respectively. Despite the ASF control measures, the ASF epidemic situation in wild boars was exacerbated. Targeted wild boar population management and active carcass searches are necessary to reduce the spread of ASF.
Mauremys reevesii (Reeves’ turtle) is an endemic freshwater turtle species found throughout East Asia. Due to a rapid population decline, the International Union for Conservation of Nature (IUCN) and the Korean government have classified this species as Endangered (EN). The reported largest population size of M. reevesii in the Republic of Korea was previously estimated to be approximately 20-30 individuals. Our study assessed the population size and structure of M. reevesii at Geumho Reservoir, Republic of Korea, using a capture-recapture data. A total of 433 M. reevesii were incidentally captured during a 35-week trapping process conducted from March to October 2023. The sex ratio of the captured population exhibited a male bias of 1.3 : 1. Sexual size dimorphism was observed only in body weight. Individuals were recaptured up to 11 times during the study period, with males and females being recaptured at an average of 2.1±2.0 times and 1.5±0.9 times, respectively. The estimated population size of M. reevesii in Geumho Reservoir was approximately 891 turtles. The absence of notable sexual size dimorphism and significant sex ratio differences suggests that the population in this area may have been established relatively recently. Compared to previous records, the population in Geumho Reservoir represents the largest single population of M. reevesii, both within the Republic of Korea and globally.
현대 군사 환경에서 병력 보충 방식은 부대의 전투력 유지와 직접적인 연관이 있으며, 한국군의 경우 기존의 개인보충 방식이 부대 응집력 저하 및 전투력 약화의 원인으로 작용하고 있다. 특히, 2021년 12월 병 복무기간이 18개월로 단축된 이후, 개인보충 방식이 과거와 동일하게 유지되면서 연간 병력 교체율이 66%를 상회하게 되었으며, 이로 인해 부대의 전투 효율성 유지가 더욱 어려워지고 있다. 또한, 현재 동원 부대의 편성 방식 역시 개별 동원지정을 기반으로 하고 있어 부대 고정율이 낮고, 짧은 동원훈련 기간으로 인해 유사시 신속한 전투력 발휘에 한계가 존재한다. 이에 따라, 기존 개인보충 방식의 한계를 극복할 수 있는 새로운 병력 보충 방식의 도입이 필요하다. 본 연구는 한국군의 현역 및 동원전력 보충 방안으로 ‘중대단위 부대보충’ 개념을 제안하고, 이를 통해 전투력 유지 및 응집력 강화를 도모하는 방안을 모색하였다. 이를 위해 독일, 이스라엘, 미국 등의 부대보 충 사례를 분석하고, 이를 한국군에 적용할 수 있는 정책적 시사점을 도출하였다. 또한, 부대보충 방식이 부대의 전투력과 조직 응집력에 미치는 영향을 실증적으로 분석하기 위해 전투력 평가 실험을 설계하고, 경제적 타당성 분석을 수행하였다. 분석 결과, 중대단위 부대보충 방식은 병력 운영의 안정성을 높이고, 장기적으로 전투력 유지 및 국가 방위력 강화에 기여할 수 있는 것으로 평가되었다. 본 연구는 한국군의 병력 보충 방식에 대한 새로운 접근법을 제시하고, 부대보충 방식이 기존 개인보충 방식에 비해 효과적인 대안이 될 수 있음을 실증적으로 검토하였다. 이를 통해, 향후 군사정책 수립 및 동원체제 개편에 있어 중요한 자료로 활용될 수 있을 것으로 기대된다.
In this study, 41 individuals in 7 locations within CP, MG, UC, and DN map sheets were observed. The MG map sheet had the highest number (n=13) of individuals, while the CP-3 site on the CP map sheet had the lowest number (n=1) of individuals. Land use analysis indicated that the MG site with the highest number of individuals had a high percentage (70.56%) of forest land areas with a small percentage (12.63%) of farmland areas. The CP-3 site with the lowest number of individuals had a small percentage (26.47%) of farmland areas. It also had the highest percentage (32.13%) of residential and commercial areas, covering 19,616 m2. Measurement results of the physical habitat environment for B. karubei indicated a mean substrate of -2.1 (Φm), an average water depth of 63.0 cm, and a flow velocity of 0.2 m s-1. The association rule analysis for co-occurring species revealed that Semisulcospira coreana, Ecdyonurus kibunensis, and Goera japonica had the highest associations among lotic species, while Limnodrilus gotoi and Calopteryx japonica demonstrated the highest association among lentic species.
The aim of this study was to evaluate the carbon storage capacity of broad-leaf forests in Republic of Korea through the analysis of studies related to carbon storage and carbon uptake, and to analyse the relationship between climatic factors affecting carbon storage capacity. We analysed the results of each previous study by summarising the research results of 55 previous studies collected through search, and organised the study area information and climate factors (elevation, average annual temperature, annual precipitation, etc.). And the carbon storage and net primary production of the above and below-ground and the whole plant were evaluated and the correlation with the climatic factors was statistically analysed. The analysis showed that the carbon storage of broad-leaved forests was positively correlated with altitude and negatively correlated with precipitation. These results mean that carbon accumulation in plants is more effective at higher altitudes with lower temperatures, and that broad-leaf forests are able to adapt and perform carbon storage functions in areas with low precipitation. Carbon uptake was negatively correlated with altitude and positively correlated with temperature. This means that the carbon absorption capacity of broad-leaved forests is greatly affected by temperature, and that the carbon absorption potential is greater in lowlands. Therefore, policies should be actively established to increase and preserve the carbon storage capacity of forests by considering the characteristics of the ecosystem functions of broadleaf forests and climate factors. The results of this study are expected to contribute to the understanding of the carbon cycle of broad-leaved forests and to the development of management measures, and to provide scientific data for carbon neutrality.
This study reassessed two KBA sites in the Republic of Korea following the KBA guidelines. Both sites met the sub-criteria A1a, A1b, and D1a, confirming their status as KBA. These assessments provide a scientific foundation for discussions on designating new protected areas or expanding existing ones. Through this study, we confirmed that continuous biodiversity conservation is essential for Geum-gang river and estuary and Yubu-do to maintain their KBA status. This KBA reassessment provides an important scientific foundation for discussions on the designation of new protected areas or the expansion of existing ones. Furthermore, this study was based on a previously evaluated taxonomic group, birds, highlighting the need for future assessments to include other biological taxa and evaluation criteria, such as Criteria B or E, for a more comprehensive analysis.
Tricholoma matsutake is a commercially valuable fungus that produces gourmet mushrooms. The artificial cultivation method that is currently used to produce fruiting bodies involves the transplantation of pine trees infected with T. matsutake from their natural habitats and the successful infection of young pine trees and mushroom production have been reported in Hongcheon. In this study, T. matsutake genetic diversity and relationships in this region were investigated. A genotype analysis was conducted on 25 fruiting bodies collected from an area approximately 2.56 km2 in size using 10 simple sequence repeat (SSR) markers. The analysis revealed 25 genotypes and 23 alleles with mean observed (HO) and expected (HE) heterozygosities of 0.312 and 0.293, respectively. The average polymorphism information content (PIC), which indicates marker polymorphism, was 0.257. A phylogenetic analysis showed no clear correlation between collection location and genetic distance; a spatial autocorrelation analysis indicated no significant genetic structure within 1600 m; and the Mantel test showed no significant correlation between genetic and geographic distances. These results were consistent with previous reports on Japanese populations. This study provides insights into the genetic diversity and structure of T. matsutake at a local scale and highlights the need for further studies across broader geographical ranges.
본 연구는 저출산고령사회에 직면한 우리나라의 상황 안에서 향후 우 리나라의 사회보장제도에 대한 개선방안을 고찰하고 제안하는데 목적이 있다. 연구결과, 첫째, 보장목적별 접근방안으로는 소득보장제도는 사회 보험제도 유지하되, 아동수당제도와 장애인수당제도의 수정개편 및 기초 연금제도를 확대수정한 기본생활보장연금제도(가칭)가 필요하다. 둘째, 경제활동기별 접근방안으로 경제활동준비기에는 아동보험제도(가칭) 신설 과 아동수당제도의 수정개편이 필요하며, 경제활동휴지기에는 현행 기초 연금제도를 수정개편한 직업과 직종의 유무에 상관없는 정액제 기본생활 연금제도(가칭)와 국민연금제도와 특수직역연금제도를 통합한 직종에 구 분없이 모든 직장가입자를 대상으로 하는 정률제 생활안정연금제도(가칭) 의 수정개편이 필요하다.
Freshwater environments are rich ecosystems that support diverse microbial communities, including members of the phylum Actinomycetota critical for nutrient cycling, organic matter decomposition, and water quality maintenance. Actinomycetota known to produce numerous bioactive secondary metabolites are valuable in biotechnology, medicine, and agriculture. Despite their significance, the diversity and distribution of Actinomycetota in freshwater habitats, especially in the Republic of Korea, are underexplored. This study aimed to report the isolation and characterization of 22 previously unrecorded bacterial species of Actinomycetota from various freshwater environments in Korea. Using standard dilution plating techniques on six different culture media, 22 bacterial strains were isolated, incubated, and characterized based on colony and cellular morphologies, Gram staining, and biochemical properties. Genomic DNA was extracted and the 16S rRNA gene was sequenced to determine species identity using the EzBioCloud service with a cutoff of 98.7% sequence similarity for classification as unreported species. These strains were phylogenetically diverse, belonging to two classes, ten orders, and eighteen genera. This study enhances our understanding of bacterial diversity in freshwater ecosystems and underscores the importance of exploring microbial diversity in underexplored habitats, potentially leading to discovery of novel bioactive compounds. Findings of this study contribute valuable insights into ecological roles and biotechnological potential of Actinomycetota in freshwater environments.
Rapeseed (Brassica napus L.) oil is mostly refined oil (RO). However, with increasing interest in health, the consumption of cold-pressed oil (CPO) without chemical refining is increasing in Korea. In this study, quality characteristics of CPO from rapeseed varieties ‘Jungmo7001’, ‘Jungmo7002’, ‘Jungmo7003’,and ‘Yuryeo’were evaluated and compared with RO, a commercial product. L-value and a-value were lower while b-value was significantly higher for CPO than those for RO. Analysis of fatty acid compositions of each oil revealed that CPO from ‘Yuryeo’contained the highest oleic acid at 74%. Analyses of contents of bioactive compounds in CPOs and RO revealed that contents of tocopherol, β-carotene, and canolol were the highest in CPOs from ‘Jungmo7003’, ‘Jungmo7002’, and ‘Jungmo7001’at 55.5, 0.3, and 0.2 mg/100 g, respectively. In addition, CPOs contained higher contents of bioactive compounds than RO, suggesting that CPO could provide health benefits. The induction period of CPOs measured using Rancimat were 9∼52% longer than that for RO, indicating that CPOs had a higher oxidative stability under given conditions. These results could be used to obtain basic data on quality of domestic rapeseed varieties.
As part of the research program “Freshwater Prokaryotic Organisms Research and Discovery,” freshwater samples were collected from the Nakdonggang River. After plating the samples on several culture media and incubating aerobically, approximately 900 bacterial strains were isolated and identified using 16S rRNA gene sequences. Among the bacterial isolates showing higher than 98.7% 16S rRNA gene sequence similarity with those of already confirmed bacterial species previously unreported in Korea, 29 strains were selected. These strains were phylogenetically diverse and belonged to 3 phyla, 6 classes, 13 orders, and 21 genera. At the genus level, these previously unreported species were found to be affiliated with Novosphingobium, Sphingomonas, Polymorphobacter, Croceibacterium, Devosia, Endobacterium, Agaricicola, Bradyrhizobium, Paracoccus, and Pseudotabrizicola of the class Alphaproteobacteria; Undibacterium, Azonexus, and Dechloromonas of the class Betaproteobacteria; Acinetobacter and Budvicia of the class Gammaproteobacteria; Streptomyces, Nocardioides, Mycobacterium, and Cellulomonas of the phylum Actinomycetota; Flavobacterium and Pedobacter of the phylum Bacteroidota. These species were further characterized by examining their Gram reaction, colony and cell morphologies, biochemical properties, and phylogenetic positions. Detailed descriptions of these 29 previously unreported species are provided.
The Sinology circle in the Republic of Korea (ROK) has always been paying close attention to the study of Chinese classical literature, especially the study of the works of key writers. Wang Wei research shows distinct temporal characteristics at different times. With the establishment of diplomatic relations between the ROK and China in 1992 as the demarcation point of time, this article summarizes and analyzes the research in Wang Wei in the Korean academic community, consisting of two major periods. On the whole, after the official establishment of diplomatic relations between the ROK and China, the research in Wang Wei in the ROK truly got on the right track. Especially in the 21st century, the research in Wang Wei in the ROK showed signs of prosperity, and with the increasing exchange and cooperation with China and other countries in Sinology research, has become an important component of cross-cultural literary research. It involves extensive content and research perspectives, including the relationship between Wang Wei’s poetry and his paintings, the overall characteristics of Wang Wei’s poetry, the imagery of Wang Wei’s poetry, the relationship of Wang Wei and his poetry with Buddhism, comparative studies of Wang Wei’s poetry, and the reception and dissemination of Wang Wei by Korean poets. This article classifies and analyzes these research findings, sorts out the development process of the research in Wang Wei in the Sinology circle in the ROK, analyzes its current research status, and explore its future development focus and direction.
독도는 한반도와는 다른 기후와 생태계로 특이성과 고유한 가치를 지닌다. 본 연구는 독도의 전반적인 생태계를 관찰하고, 주요 식생에 고정조사구 를 지정하여 시계열적인 변화를 모니터링함으로써 독도 식생 경쟁 및 천이 연구에 기초자료를 제공하고자 하였다. 연구 결과, 독도의 식생은 시기와 계절에 따라 다양하게 변화하는 것으로 확인되었다. 독도 외부유입종인 큰이삭풀, 왕호장근의 세력 확산이 확인되었으며, 산림생태계복원사업 시행으 로 식재된 사철나무, 섬괴불나무의 군락이 소규모 안정적으로 정착한 것으로 나타났다.
This study aimed to develop the in vitro method using domestic commercial diets to estimate nutrient digestibility in dogs. The existing in vitro method were tested and compared with literature data to develop new in vitro method. The development of in vitro method progressed as follows: modification of pepsin solution to an activated form and supplementation with 1% lipase. All the in vitro method progressed to 4 hours of stomach simulation and 2 hours of small intestine simulation. In vivo digestibility was measured using the same diets as beagle dogs. The supplementation of lipase methods showed significantly improved (p < 0.05) DM, OM, and EE than the existing and modified pepsin solution methods. The correlation between in vitro and in vivo data in DM, OM, and EE digestibility was high (r2 = 0.889, 0.907, and 0.721, respectively), and the correlation between in vitro and in vivo data in CP and GE digestibility was medium (r2 = 0.681 and 0.536, respectively). The current in vitro method is similar to in vivo digestibility and helps potentially predict digestibility for dogs. In conclusion, this developed in vitro method suggests that it can help estimate the nutrient digestibility of dogs' diets without in vivo experiments.
말라리아는 Anopheles 모기들에 의해 전파되며, 대한민국에서는 코로나 팬데믹 기간 동안(2020~2022) 약 200~300명대의 말라리아 환자가 발생하였으나, 지난 2023년에는 그 수가 폭증해 약 800명의 환자가 발생하였다. 현재까지 모기를 방제하기 위한 가장 효율적인 수단은 살충제를 사용한 방제이나, 지속적으로 이러한 화합물에 노출된 모기 개체군은 살충제에 저항성을 갖게 되는 것으로 알려져 있다. 이에 본 연구에서는 대한민국의 주요 말라리아 발생 지역인 비무장지대 부근 및 이외 지역인 용산, 평택, 오산에서 채집을 진행하였으며, 채집된 An. sinensis에 대해서 살충제 저항성과 관련되어 있다고 알려진 유전자인 acetylcholinesterase-1(ace-1)와 voltage-gated sodium channel(vgsc) 영역에 대한 저항성 돌연변이 보유 여부를 각각 확인하였다. 실험 결과 채집된 모든 지역에서 G119S(ace-1), L1014F,C(vgsc) 돌연변이가 발견되었으며, 그 빈도는 계절과 장소에 따라 차이를 나타내었다. 본 실험 결과는 향후 말라리아 감염 억제를 위한 매개체 연구에 활용될 수 있을 것으로 기대된다.