Vibrio vulnificus는 그람 음성 세균의 호염성 세균으로, 5월에서 10월 사이 해수 온도가 18oC 이상이고 염도가 15- 25 practical salinity units (psu)일 때 가장 활발하게 증식 한다. 전 세계적으로 해수, 강 하구, 갯벌 등 다양한 해양 환경에 서식하며, 굴, 전복 등 해산물에서 자주 검출되는 경향이 있다. 지속적인 지구온난화로 인한 해수 온도의 상 승으로 V. vulnificus의 분포 범위가 점차 확장되고 있으며, 그에 따라 비브리오 패혈증 감염에 대한 위험도가 증가하 고 있다. 본 연구에서는 수산물에서 V. vulnificus 분리, 항 생제 감수성 검사, MLST 분석, 전장 유전체 분석을 통한 병원성 유전자 확인, MIC를 통한 항생제 내성 유전자 분 석, 더 나아가 bv-brc에 등록된 아시아에서 분리된 V. vulnificus 균주들과 함께 cgMLST 분석을 진행하였다. 2023 년4월-7월까지 서울, 경기도 및 충청도 지역의 대형마트에 서 유통되는 수산물 시료 총 84건에서 V. vulnificus가 바 지락에서 총2주(2.4%) 분리되었으며, 2균주 모두 colistin 에 강한 저항성을 보였으나, V. vulnificus의 치료에 사용되 는 ciprofloxacin, tetracycline, chloramphenicol 항생제에 내 성을 보이지 않았다. Whole genome sequencing 분석 결 과, 유전자 상 두 균주는 동일한 클론으로 확인되었으며, multi-locus sequencing typing 결과 기존에 보고되지 않은 새로운 sequence type으로 확인되었다. Virulence gene 분 석 결과, 총123개의 병원성 유전자가 확인되었으며, 그 중 중요한 병원성 유전자 rtxA, vvhA, viuB, ompU유전자가 확 인되었다. 항생제 내성 유전자 분석 결과 분리된 두 균주 에서 모두 tet(34), tet(35), varG, norM 내성 유전자가 확 인되었다. cgMLST 분석을 진행한 결과 본 연구에서 분리 된 두 균주는 동일 cluster로 확인되었고, 기타 국내 및 아 시아 지역에서 분리된 V. vulnificus를 포함한 분석에서 균 주 간 역학적 연관성은 관찰되지 않았다. 이는 V. vulnificus 가 해수의 흐름을 타고 이동하여 분포 범위가 넓고 특정 지역에 일정한 특징을 가진 균이 밀집되지 않기 때문으로 보인다. 따라서 V. vulnificus로 인해 매년 사망자와 환자가 발생하는 것은 V. vulnificus가 가지는 잠재적인 위험성을 보여주고 있고, 본 연구결과가 향후 질병 발생 시 V. vulnificus의 연구에 도움이 될 것으로 보이며, 지속적으로 V. vulnificus 검출 연구, 항생제 내성 모니터링이 필요할 것으로 사료된다. 해산물을 통한 V. vulnificus 감염 위험성 이 증가하고 있는 상황에서 국내 수산물을 통한 V. vulnificus 전파 위험도에 대한 체계적 연구는 부족하다. 따라서 본 연구 결과는 수산물 생산 및 유통 단계에서 V. vulnificus 의 모니터링 및 위험도 평가의 중요성을 제시한다.
Chamaecyparis obtusa is one of the economical conifers planted in Korea due to its good quality timber and wood characteristics. Individuals of C. obtusa containing high terpenes (HT) and low terpenes (LT) were selected for by colorimetric method. The HT of C. obtusa was delayed in wilting against various abiotic stresses compared to the LT plants. The HT group exposed to UV did not significant influence the chlorophyll content, and the chlorophyll value was higher in the HT group than the LT group. Also, chilling treatment (5℃) did not significant influence on the chlorophyll content. However treatment at -4℃ showed relatively low chlorophyll content in the LT group than the HT group. Plants exposure to high temperature was not a difference between the HT and the LT group. However, treatment at 38℃ influenced the chlorophyll content that was increased exposure time-dependently. In salt treatments, chlorophyll in the HT group was lower at high concentrations (300 and 500 mM) of NaCl. However, chlorophyll content increased to slightly in treatment time-dependently, which is 6.7% to 40%. H2O2 treatment has been a negative effect on the chlorophyll content in the HT group. All concentration of H2O2 decreased the chlorophyll content of 5% to 35%. Plants containing high terpenoids were resisted against some abiotic stress such as salt and H2O2. Our results implied that terpenoids could cause various abiotic stress resistance. These results could be utilized for efficient management and biomass production during forest silvicultures.
Stem and root of elm trees have used as traditional medical materials, but there is little information on the distribution and resources of habitats. Korean native growing Ulmus spp. (U. davidiana var. Japonica, U. parvifolia, U. davidiana, and U. macrocarpa) genetic resources studied through The National Forest Inventory of Korea data and field survey. The distributions of U. davidiana var. japonica according to elevation distributed evenly. Both U. parvifolia and U. davidiana were inhabited mostly at less than 200 m of altitude. Each Ulmaceae species widely were distributed nationwide, but a dominant species was different depending on locals. It observed that Ulmaceae inhabits mainly in steep slopes of 31-45 degrees. Most of the habitats regenerated by natural seeding and the most abundant species were a codominant tree. Distribution of trees in U davidiana var. japonica was 7 m-13 m, and in young U. parvifolia and U. macrocarpa, more than 25% of young trees less than 7 m observed. The distribution of the diameter of breast height of the U. davidiana var. japonica was 46.4% for 11-20 cm, 52.6% for 11-20 cm in U. parvifolia. The average T/R ratio was 0.83, and the mean weight ratio of root bark was 62%. As the results of this study, the domestic Ulmaceae biomassare very small. It is difficult to harvest in that the habitat on the slope. Thus, it is too hard to develop functional materials using biomass at present. Therefore, it is necessary to develop technology for the selection and propagation of elite trees of Ulmaceae.
This study was performed to analyze a saltiness enhancement at the same salt content through multiple emulsion. We compared the samples with different conditions to determine the optimum stability conditions of water-in-oil through layer separation rate, microscopic observation and size analysis. Four electrolytes such as NaCl, KCl, MgCl2, and CaCl2 were used and agar contents ranged from 0 to 1% were experimented at different volume ratios including 5:5, 4:6, 3:7, 2:8, and 1:9 of water and oil. As a result of this study, the droplet size according to the electrolyte type did not show significant differences (p<0.05). Therefore, KCl was used to facilitate in-body excretion of NaCl in the outer water phase, and corn oil containing 8%(w/w) polyglycerol polyricinoleate was used as oil phase. When the volume ratio of water and oil was 3:7, 2:8, and 1:9, the layer separation rate was relatively slow and droplet size was also small. It reveals that the particle size becomes smaller as the water volume ratio decreases. However, considering the amount of water to be stored and eluted on the inner water, appropriate volume ratio of water and oil should be adopted to 3: 7. At Microscopic observation depending on agar concentrations, small particle size appeared at 0.2% and 0.4% agars. When the water and oil ratio was fixed at 3:7, the particle size was measured at 0.2% and 0.4% agar using a zeta sizer. In conclusion, the droplet size of 0.2% agar was smaller than 0.4%. Therefore, the most stable water-in-oil emulsion was obtained with 0.2% agar, when water to oil ratio was 3:7.