• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.225-236
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• 2013

Among several bacteria examined, an antibacterial-producing Lactobacillus strain with probiotic characteristics was selected and identified based on 16S rRNA gene sequencing. Subsequent purification and mode of action of the antibacterial compounds on target cells including E. coli were investigated. Maximum production of the antibacterial compound was recorded at 18 h incubation at $30^{\circ}C$. Interestingly, antibacterial activity remained unchanged after heating at $121^{\circ}C$ for 45 min, 24 h storage in temperature range of $70^{\circ}C$ to room temperature, and 15 min exposure to UV light, and it was stable in the pH of range 2-10. The active compounds were inactivated by proteolytic enzymes, indicating their proteinaceous nature, and, therefore, referred to as bacteriocin-like inhibitory substances. Isolation and partial purification of the effective agent was done by performing ammonium sulfate precipitation and gel filtration chromatography. The molecular mass of the GFC-purified active compound (~3 kDa) was determined by Tris-Tricine SDS-PAGE. To predict the mechanisms of action, transmission electron microscopy (TEM) analysis of ultrathin sections of E. coli before and after antibacterial treatment was carried out. TEM analysis of antibacterial compounds-treated E. coli demonstrated that the completely altered bacteria appear much darker compared with the less altered bacteria, suggesting a change in the cytoplasmic composition. There were also some membrane-bound convoluted structures visible within the completely altered bacteria, which could be attributed to the response of the E. coli to the treatment with the antibacterial compound. According to the in vivo experiments oral administration of L. plantarum HKN01 resulted in recovery of infected BALB/c mice with Salmonella enterica ser. Typhimurium.

• 셀메드
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• 제2권2호
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• pp.14.1-14.7
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• 2012

Cordycepin, a nucleoside derivative, was extracted from $Cordyceps$ $sinensis$, and then proved to be a bioactive compound present in traditional Chinese medicine Cordyceps. Early investigations revealed cordycepin possessed anti-microbial activity mainly by inhibiting nucleic acid synthesis. Although cordycepin is not used as antibacterial agents in clinic, its other pharmacological effects and possible mechanisms have gradually been deeply studied. This review serves to summarize the research progress of cordycepin.

• Fisheries and Aquatic Sciences
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• 제26권1호
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• pp.1-23
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• 2023

Marine bioactive substances (MBS), such as phlorotannins, collagens, peptides, sterols, and polysaccharides, are increasing attention as therapeutic agents for several diseases due to their pharmacological effects. Previous studies have demonstrated the biological activities of MBS including antibacterial, anticoagulant, antidiabetic, antimicrobial, anti-inflammatory activities. Among numerous human diseases, periodontitis is one of the high-prevalence inflammatory diseases in the world. To treat periodontitis, several surgeries (bone grafting, flap surgery, and soft tissue graft) are usually used. However, the surgery for patients with chronic periodontitis induces several side effects, including additional inflammatory responses at the operated site, chronic wound healing, and secondary surgery. Therefore, this review assessed the most recent trends in MBS using Google Scholar, PubMed, and Web of Science search engines to develop marine-derived therapeutic agents for periodontitis. Further, we summarized the current applications and therapeutic potential of MBS to serve as a reference for developing novel technologies applied to MBS against periodontitis treatment.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2006년도 한국약용작물학회 공동춘계학술발표회
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• pp.540-541
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• 2006

• Toxicological Research
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• 제26권4호
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• pp.301-313
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• 2010

Growth promoters including hormonal substances and antibiotics are used legally and illegally in food producing animals for the growth promotion of livestock animals. Hormonal substances still under debate in terms of their human health impacts are estradiol-$17\beta$, progesterone, testosterone, zeranol, trenbolone, and melengestrol acetate (MGA). Many of the risk assessment results of natural steroid hormones have presented negligible impacts when they are used under good veterinary practices. For synthetic hormonelike substances, ADIs and MRLs have been established for food safety along with the approval of animal treatment. Small amounts of antibiotics added to feedstuff present growth promotion effects via the prevention of infectious diseases at doses lower than therapeutic dose. The induction of antimicrobial resistant bacteria and the disruption of normal human intestinal flora are major concerns in terms of human health impact. Regulatory guidance such as ADIs and MRLs fully reflect the impact on human gastrointestinal microflora. However, before deciding on any risk management options, risk assessments of antimicrobial resistance require large-scale evidence regarding the relationship between antimicrobial use in food-producing animals and the occurrence of antimicrobial resistance in human pathogens. In this article, the risk profiles of hormonal and antibacterial growth promoters are provided based on recent toxicity and human exposure information, and recommendations for risk management to prevent human health impacts by the use of growth promoters are also presented.

• Asian-Australasian Journal of Animal Sciences
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• 제23권6호
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• pp.700-707
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• 2010

Effects of protease-resistant antimicrobial substances (PRA) produced by Lactobacillus plantarum and Leuconostoc citreum on rumen methanogenesis were examined using the in vitro continuous methane quantification system. Four different strains of lactic acid bacteria, i) Lactococcus lactis ATCC19435 (Control, non-antibacterial substances), ii) Lactococcus lactis NCIMB702054 (Nisin-Z), iii) Lactobacillus plantarum TUA1490L (PRA-1), and iv) Leuconostoc citreum JCM9698 (PRA-2) were individually cultured in GYEKP medium. An 80 ml aliquot of each supernatant was inoculated into phosphate-buffered rumen fluid. PRA-1 remarkably decreased cumulative methane production, though propionate, butyrate and ammonia N decreased. For PRA-2, there were no effects on $CH_4$ and $CO_2$ production and fermentation characteristics in mixed rumen cultures. The results suggested that PRA-1 reduced the number of methanogens or inhibited utilization of hydrogen in rumen fermentation.

• 미생물학회지
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• 제53권4호
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• pp.273-285
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• 2017

본 연구에서는 프로바이오틱 유산균이 생산한 항균물질에 의한 바이오제닉 아민 생성균의 제어 효과와 박테리오신 및 유기산의 항균 활성에 영향을 미치는 배양 조건을 조사하였다. Lactobacillus plantarum FIL20 (64 AU/ml) 및 Lactobacillus paracasei FIL31 (128 AU/ml)의 박테리오신 용액은 Serratia marcescens CIH09과 Aeromonas hydrophilia RIH28에 각각 강한 항균 활성을 나타내었고 FIL20과 FIL31 균주로부터 얻은 배양 상등액 내에 유산 함유량은 각각 $107.3{\pm}2.7mM$과 $129.5{\pm}4.6mM$로 나타났다. 따라서 L. plantarum FIL20과 L. paracasei FIL31이 생산한 박테리오신 용액(200 AU/ml) 및 배양 상등액($200{\mu}l/ml$)의 처리에 의해 S. marcescens CIH09 및 A. hydrophilia RIH28의 균수 및 히스타민과 티라민의 생성량을 유의하게 감소시켰다(P < 0.05). 초기 pH (5.0)와 배양 온도($15^{\circ}C$)가 낮은 조건 하에서 CIH09 균주가 생산한 히스타민과 티라민의 생성량은 L. plantarum FIL20이 생산한 박테리오신 용액이나 배양 상등액 처리에 의해 유의하게 감소되었다. 또한 식염 5% 혹은 아질산 칼륨($200{\mu}g/g$)과 FIL20 유산균의 항균물질을 혼용한 경우 바이오제닉 아민을 생성하는 세균의 균수와 유해 아민 함량을 유의하게 감소시켰다(P < 0.05). 결론적으로 L. plantarum FIL20과 L. paracasei FIL31의 박테리오신 및 유기산 용액은 허들 테크놀로지에 적용하여 바이오제닉 아민 생성을 효과적으로 제어할 수 있는 생물학적 보존제로 이용될 수 있을 것이다.

• 미생물학회지
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• 제47권3호
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• pp.241-248
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• 2011

식품의 상품성과 보존을 위하여 사용하는 합성 첨가물이 소비자들의 소비 습관의 변화와 첨가물의 안전성에 대한 사회적 쟁점화로 천연의 소재를 활용한 다양한 연구와 조사가 진행되고 있다. 본 연구에서도 천연물 중 한의학의 소재로 사용되는 생약제제 79종을 사용하여 식품 중 상품성이 훼손된 음료에서 분리한 세균에 대한 항균성을 조사하였다. 13종의 Bacillus sp.와 3종의 Paenibacillus sp.에 대한 메탄올 추출물의 항균성을 조사한 결과 43종의 생약제제가 분리한 세균에 대한 항균성을 나타내었다. 이 중 8종의 한약재를 선별하고 이들을 대상으로 물, 에탄올, 메탄올과 에틸아세테이트를 추출 용매로 하여 항균성을 조사한 결과 오매, 오배자와 황련이 분리된 세균에 대한 항균성이 우수한 것으로 조사되었으며 특히 물과 에탄올을 사용한 경우에 우수한 항균성을 나타내어 이 결과를 바탕으로 이들 소재를 활용한 천연보존료의 개발 가능성을 확인할 수 있었다. 특히 다른 생약제제와 비교할 때 오매에 대한 연구가 상대적으로 미진한 것으로 판단되어 향후 지속적인 연구를 통한 제품의 개발도 가능할 것으로 판단하였다.

• 한국수산과학회지
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• 제43권1호
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• pp.33-38
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• 2010

Emerging of antibiotic resistance of pathogenic bacteria is now a very serious problem in the clinics to treat the diseases, which have been easy to cure by antibiotic treatments before. Unfortunately, antibiotics developed till now are not effective any more against the resistant bacteria. Lots of efforts to discover new antibiotics having novel and unique structures and functions are really urgent and undergoing in the whole world. In this study, we tried to screen and isolate Same unique bacterial strains producing antibacterial substances from the sea water, which is the poor environment for bacteria 10 make their growing. Three bacterial strains among 916 strains isolated showed inhibition clear zone on the marine agar plate growing pathogenic bacteria including Acinetobacter baumannii, Edwardsiella tarda, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella enterica. One of them, which was identified as Bacillus sp. DH-9 from 16S rRNA gene analysis, showed especially considerable antibacterial activity against S. aureus which is notorious for methicillin resistant S. aureus (MRSA). The growth of S. aureus was totally inhibited when the supernatant of Bacillus sp. DH-9 culture was treated on.

• Natural Product Sciences
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• 제23권3호
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• pp.151-156
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• 2017

A phytochemical study of Alphonsea cylindrica King (unreported) has led to the isolation of six alkaloids. The compounds were identified as kinabaline (1; azafluorenone alkaloid), muniranine (2), O-methylmoschatoline (3; oxoaporphine alkaloid), lysicamine (4), atherospermidine (5) and N-methylouregidione (6; 4, 5-dioxoaporphine alkaloid). The structures of the isolated compounds were determined based on the spectroscopic techniques and by comparison with data reported in the literature. Alkaloid 2 was isolated as a new derivative of azafluorenone while alkaloids 1, 3 - 6 were isolated for the first time from Alphonsea species. In addition, alkaloid 3 and 4 showed inhibition zone against Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus in disc diffusion test. The minimum inhibition concentration (MIC) values of lysicamine (4) against S. aureus, B. cereus and P. aeruginosa were found to be smaller than O-methylmoschatoline (3). Therefore, the reported antibacterial activity showed the potential of this plant as natural antibacterial agent and supported the documented traditional use of Alphonsea sp. in the treatment of diarrhea and fever.