• Journal of Microbiology
• /
• 제43권2호
• /
• pp.172-178
• /
• 2005

To determine the prevalence and genotypes of $\beta$-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pI determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced $\beta$-lactamases and had high levels of genetic diversity. Consistent with minimum inhibitory concentration patterns, we found that five ($167\%$) of thirty clones produced an extended-spectrum $\beta$-lactamase. 837- and 259-bp fragments specific to bla$_{TEM}$ genes were amplified, as determined by banding patterns of PCR amplification with designed primers. TEM­1 was the most prevalent $\beta$-lactamase and conferred resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type $\beta$-lactamases were essentially the same as the resistance levels conferred by the TEM-type alleles which had been isolated from clinically resistant strains of bacteria of the antibiotic era. Our first report on TEM-type $\beta$-lactamases of the pre-antibiotic era indicates that TEM-type $\beta$-lactamases paint a picture in which most of the diversity of the enzymes may not be the result of recent evolution, but that of ancient evolution.

• 한국양식학회지
• /
• 제22권1호
• /
• pp.79-82
• /
• 2009

한국 고유종인 각시붕어 R. uyekii와 떡납줄갱이 R. notatus로부터 유도된 정교배 및 상반교배 잡종어류의 분자생물학적 동정을 위하여 핵에서 encoding되는 RAG-1 유전자의 염기서열 분석을 실시하였다. 분석된 863 bp의 염기서열 중 각시붕어와 떡납줄갱이 사이에는 총 13개의 위치에서 염기서열 변이가 탐색되었다. 잡종어류의 RAG-1 유전자 염기서열을 분석한 결과 모계와 부계의 염기서열 차이를 보인 13개의 변이 부분에서 부모의 염기서열을 다같이 반영하는 double peaks 패턴을 보였으나 정교매체(UN 유전형)와 상반교배체(NU 유전형) 간의 염기서열 차이는 관찰되지 않았다.

• Journal of Microbiology and Biotechnology
• /
• 제31권6호
• /
• pp.867-874
• /
• 2021

Epalrestat (EPS) is a brain penetrant aldose reductase inhibitor, an approved drug currently used for the treatment of diabetic neuropathy. At near-plasma concentration, EPS induces glutathione biosynthesis, which in turn reduces oxidative stress in the neuronal cells. In this study, we found that EPS reduces neurodegeneration by inhibiting reactive oxygen species (ROS)-induced oxidative injury, mitochondrial membrane damage, apoptosis and tauopathy. EPS treatment up to 50 µM did not show any toxic effect on SH-SY5Y cell line (neuroblastoma cells). However, we observed toxic effect at a concentration of 100 µM and above. At 50 µM concentration, EPS showed better antioxidant activity against H₂O₂ (100 µM)-induced cytotoxicity, ROS formation and mitochondrial membrane damage in retinoic acid-differentiated SH-SY5Y cell line. Furthermore, our study revealed that 50 µM of EPS concentration reduced the glycogen synthase kinase-3 β (GSK3-β) expression and total tau protein level in H₂O₂ (100 µM)-treated cells. Findings from this study confirms the therapeutic efficacy of EPS on regulating Alzheimer's disease (AD) by regulating GSK3-β and total tau proteins phosphorylation, which helped to restore the cellular viability. This process could also reduce toxic fibrillary tangle formation and disease progression of AD. Therefore, it is our view that an optimal concentration of EPS therapy could decrease AD pathology by reducing tau phosphorylation through regulating the expression level of GSK3-β.

• 한국해양바이오학회지
• /
• 제14권1호
• /
• pp.25-32
• /
• 2022

The desire to be light skinned is universal among women. Asia has a long history of using skincare formulations as whitening agents. There is an imperative need to develop novel cosmetics from herbal sources due to several unpleasant side effects and high costs. As a result, this study aims to investigate the effect of Ceylon black tea extracts on melanogenesis. Five different Ceylon black tea extracts were prepared and examined for total phenolic content (TPC), total flavonoid content (TFC), DPPH radical scavenging activity, and tyrosinase inhibitory activity. Furthermore, B16F10 melanoma cells were treated with these extracts and tested for cytotoxicity and protein suppression levels. According to the results of this study, the highest TPCs were obtained from ethanol and acetone extractions (240.303 ± 1.389 ㎍/g and 240.202 ± 4.700 ㎍/g, respectively), whereas the highest TFC was obtained from acetone extraction (57.484 ± 0.413 ㎍/g). Ceylon black tea extracted with ethanol exhibited the highest inhibitory activity on tyrosinase with an IC₅₀ value of 0.277 ± 0.017 mg/mL and the highest DPPH radical scavenging activity with an EC₅₀ value of 0.009 ± 0.000 mg/mL. Furthermore, western blot results revealed that tyrosinase, TRP-1, TRP-2, and MITF protein expression levels were dose-dependently suppressed, indicating the applicability of Ceylon black tea extract as a novel melanogenesis inhibitor.

• 한국수산과학회지
• /
• 제56권5호
• /
• pp.660-666
• /
• 2023

This study aimed to examine the effect of external pop-up satellite archival tags (PSATs) attachment and water temperature on the oxygen consumption rate (OCR) of the olive flounder (mean body weight 2281.7 g). The OCRs of fish were measured under conditions of three different water temperature conditions (15, 20, and 25℃) and two different tagging methods [non-tagging, control; bio-logger external attachment with a miniature PSAT (dummy mrPAT), BEA] using a closed flow-through respirometer. The OCRs of fish linearly increased with the increase in water temperature in both the control and BEA (P<0.001); however, the OCRs of BEA were approximately 1.8-1.9 times lower than those of the control at each water temperature (P<0.001). The Q₁₀ values of the control and BEA were the highest in the water temperature range of 15 to 20℃, but sensitivity to water temperature changes was higher in BEA than in the control. The metabolic energy loss rate (MEL) of fish increased with increasing water temperature regardless of external tagging, but the MEL of the control was higher than that of BEA (P<0.001). These results demonstrate that OCR, thermal sensitivity, and energy expenditure are all affected in adult olive flounder with external PSAT attachment.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XII)
• /
• pp.495-495
• /
• 2003

• 환경생물
• /
• 제41권4호
• /
• pp.386-399
• /
• 2023

미세플라스틱과 나노플라스틱(NMPs)은 해양생물에 대한 생식 방해, 산화적 스트레스 등의 부정적 영향을 줄 수 있어 해양생태계의 유해오염물질 중 하나로 간주된다. 전 지구적 기후변화로 해수 온도가 상승하고 있음에도 불구하고 미세플라스틱과 온도변화 간의 독성학적 상호 작용에 대한 연구는 제한적이다. 따라서, 본 연구에서는 기수산 물벼룩 Diaphanosoma celebensis에 대한 NMPs(polystyrene beads; 0.05-, 6-㎛)의 온도 상승에 따른 독성을 개체 및 유전자 수준에서 확인하였다. 개체 수준에서의 첫 생식 시점은 온도 상승에 의해 빨라지는 양상을 보였으나 35℃ 온도 조건에서 PS beads에 노출된 경우 유의하게 지연되었다. 총 산란 수는 30℃, 0.05-㎛ PS beads에 노출된 경우에서만 유의하게 감소하였다. 상호작용 분석결과 첫번째 생식 시점과 항산화 및 열충격 단백질 유전자(GSTS1 및 Hsp70) 및 ecdysteroid 경로 관련 유전자(EcR_A, EcR_B, 및 CYP314A1)가 온도 및 PS 입자 크기에 주로 영향을 받는 것으로 나타났다. 이러한 결과는 미세플라스틱이 크기 의존적인 독성을 가지고 있음을 보여줌과 동시에 온도 증가로 인해 독성이 강화될 수 있음을 의미한다. 본 연구는 미세플라스틱의 독성을 평가할 때 수온 등 다양한 요소 또한 고려되어야 한다는 점을 제시하였으며, 해양동물 플랑크톤에 대한 수온과 미세플라스틱의 복합적 독성 상호작용에 대한 이해를 제공할 수 있을 것이다.

• Journal of Life Science
• /
• 제10권1호
• /
• pp.24-27
• /
• 2000

For the rapid diagnosis of vibriosis in penaeid shirmp, the indirect fluorescent antibody technique(IFAT) was established to detect Vibrio alginolyticus. The titers of the antisera used for this experiment were above 1280. Vibrio alginolyticus possesses the specific antigen, and also have antigens shared with other strains. When an V. alginolyticus-infected adult shirmp was tested by IFAT, V. alginolyticus was detected mainly in the muscle tissues near the injection point and the haemolymph but only few in other tissues. This result indicates that the pathogen bacteria could be detected by IFAT. Thus, it is suggested IFAT is more convenient and sensitive method than conventional plate method for the diagnosis of induced Vibrio infection in the penaeid shrimps.

• Journal of Microbiology and Biotechnology
• /
• 제10권3호
• /
• pp.307-311
• /
• 2000

Abstract Extracellular chitinase was purified from the culture liquid of the marine bacterium, Bacillus sp. LJ-25 , and its enzymatic properties were examined. The purified chitinase exhibited a single band on SDS-PAGE and the molecular weight was estimated to be approximately 50 kDa. The optimum pH and temperature for the enzymatic activity were 7.0 and $35^{\circ}C$, respectively. The activity of the chitinase was strongly inhibited by $Zn^{2+}$ and slightly inhibited by $Ba^{2+},{\;}Co^{2+},{\;}Mn^{2+},{\;}and{\;}Cu^{2+}$. The purified chitinase did not hydrolyze $p-nitrophenolN-acetyl-{\bata}-D-glucosaminide{\;}(GlcNAc)_2$ and Micrococcus lysodeikticus cells, which are known to be the substrates for exo-type chitinase. Among the hydrolyzates of colloidal chitin, $(GlcNAc)_2$ was in the highest concentration with small amounts of GlcNAc and $(GlcNAc)_3$..

• Journal of Microbiology and Biotechnology
• /
• 제19권7호
• /
• pp.675-680
• /
• 2009

There is considerable interest in the isolation of potent radical scavenging compounds from natural resources to treat diseases involving oxidative stress. In this report, four new fungal metabolites including one new bisdihydroanthracenone derivative (1, eurorubrin), two new seco-anthraquinone derivatives [3, 2-O-methyl-9-dehydroxyeurotinone and 4, 2-O-methyl-4-O-(${\alpha}$-D-ribofuranosyl)-9-dehydroxyeurotinone], and one new anthraquinone glycoside [6,3-O-(${\alpha}$-D-ribofuranosyl)-questin], were isolated and identified from Eurotium rubrum, an endophytic fungal strain that was isolated from the inner tissue of the stem of the marine mangrove plant Hibiscus tiliaceus. In addition, three known compounds including asperflavin (2), 2-0-methyleurotinone (5), and questin (7) were also isolated and identified. Their structures were elucidated on the basis of spectroscopic analysis. All of the isolated compounds were evaluated for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity.