• 한국미생물·생명공학회지
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• 제35권4호
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• pp.339-346
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• 2007

메주로부터 항곰팡이 활성을 보이는 균주 1종과 이에 감수성을 나타내는 곰팡이 3종을 분리하였다. 분리된 균주는 형태학적, 생화학적 특성 조사와 16S rRNA 염기서열 결정을 통한 균주 동정결과 Bacillus subtilis MJP1으로 명명하였고, 3종의 곰팡이는 ITS-5.85 rRNA염기서열 분석을 통하여 Aspergillus petrakii PF-1, A. ochraceus PF-2, 그리고 A. nidulans PF-3로 명명하였다 B. subtilis MJP1은 곰팡이 에 대한 강한 저해활성 뿐만 아니라 Candida 속 효모들과 그람 양성균에 대한 넓은 범위의 저해활성을 나타내었다. B. subtilis MJP1의 생육에 따른 항균 활성을 측정한 결과 항진균 활성은 배양 16시간부터 최대 활성(3,200 AU/ml)을 나타내어 균이 사멸기에 접어든 후에도 활성을 그대로 유지한 반면, 항세균 활성은 대수기 중반인 12시간부터 25시간까지 가장 높은 활성 (1,600 AU/ml)을 보이다가 72시간 이후에는 활성을 상실하였다. pH 안정성 실험에서 항진균 활성과 항세균 활성 모두 pH $6{\sim}10$ 구간에서 비교적 안정한 결과를 보였으나, 열처리 실험에서 항진균 활성은 영향을 받지 않은 반면, 항세균 활성은 $30^{\circ}C$ 이상의 온도에서는 불안정한 결과를 보였다. 각종 효소에 대한 안정성 실험에서 항진균 활성은 어떠한 효소에도 영향을 받지 않았으나, 항세균 활성은 단백분해효소 처리 후에 활성이 실활 됨으로써 항균 물질이 단백질성 물질임을 추정하였다. $C_{18}$ Sep-Pak column으로 부분 정제한 항균 물질이 항진균 활성과 항세균 활성을 나타내므로 소수성을 가지는 물질임을 알 수 있으며, Tricine-SDS-PAGE및 direct detection을 통하여 항진균 물질의 분자량은 약 2.4 kDa 정도이며, 항세균 물질의 분자량은 약 4.5 kDa으로_ 확인되었다. 따라서 B. subtilis MJP1은 항진균 활성과 항세균 활성을 가진 bacteriocin-like substances를 생산함을 알 수 있고 이와 같은 새로운 항미생물 물질은 천연 식품보존제 및 사료보존제 뿐만 아니라 항생제 대체 의약품으로도 활용이 기대되며, 이를 위하여 향후 이 물질들의 보다 정확한 구조 및 특성 규명 등의 연구가 필요하다.

• 한국균학회지
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• 제24권4호통권79호
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• pp.310-321
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• 1996

토양으로부터 항진균 활성을 나타내는 5종류의 Pseudomonas cepacia 균주 AF027, AF069, AF2001, AF2011, SD02가 분리되었으며 이들은 각각 cyclic lipopeptide계 항진균 물질 CLP027A, CLP069A, Cepacidine A, CLP2011A, CLP02A를 생산하였다. 조사된 P cepacia 균주들은 배지중에 함유된 질소원 및 탄소원의 종류에 따라 항진균 물질 생산성에 현저한 차이가 있었는데, 질소원으로서는 polypeptone-S, 탄소원으로서는 glucose와 fructose가 생산성 증대에 가장 효과적이었다. 항진균물질 $CLP069A_1$과 $CLP069A_2$는 각각 분자량이 1215와 1199이며, 아미노산 조성, UV spectrum, IR spectrum 및 항진균 스펙트럼에 있어서, Xylocandin $A_1,\;A_2$와 일치하였으며, CLP027 $A_1$과 $A_2$ 또한 이러한 물리 화학적 특성이 Cepacidine A와 완전히 일치함으로써 동일 물질로 생각된다. $CLP2011A_1,\;A_2$와 $CLP02A_1,\;A_2$는 아미노산 조성 및 항진균 스펙트럼이 Xylocandin $A_1,\;A_2$와 다르고, Cepacidine $A_1,\;A_2$와는 항진균 스펙트럼에서 현저하게 차이가 났다. CLP2011A, CLP02A가 분자량, 아미노산 조성, UV spectrum, IR spectrum에서 Cepacidine A와 동일하지만 항진균 스펙트럼이 상이한 것은 이들이 다른 물질임을 시사하며, 이는 aliphatic side chain이 Cepacidine A의 그것과 다른 데에서 비롯된 분자구조의 상이함에서 기인된 것으로 추론된다.

• 생명과학회지
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• 제21권10호
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• pp.1481-1486
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• 2011

버섯 생산 후 발생되는 부산물인 팽이버섯 수확 후 배지로부터 7종의 고온성 균주를 분리하였으며 이 중 곰팡이독소를 생성하는 Asp. flavus와 Asp. ochraceous에 대한 항균활성이 높으면서 xylanase와 cellulase 생성능이 우수한 균주를 최종 선발하여 UJ03으로 명명하였다. Bacillus ID kit와 VITEK 2 system를 이용하여 분리균 UJ03의 생리적 생화학적 특성을 조사한 결과 분리균 UJ03은 Bacillus 속과 유사한 특징을 나타내었으며 16S rDNA 염기서열 분석 결과에서는 B. amyloliquefaciens와 98.9%의 상동성을 나타내었다. 이와 같은 결과를 종합하여 분리균 UJ03은 Bacillus sp. UJ03으로 동정되었으며 분리균 UJ03이 생성하는 항균물질은 TLC와 HPLC 분석에서 Bacillus 속 균주가 생성하는 펩타이드성 항균물질인 iturin A와 유사한 특성을 나타내었다.

• Journal of Microbiology and Biotechnology
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• 제30권3호
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• pp.417-426
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• 2020

Bacillus amyloliquefaciens is an important plant disease-preventing and growth-promoting microorganism. B. amyloliquefaciens WS-8 can stimulate plant growth and has strong antifungal properties. In this study, we sequenced the complete genome of B. amyloliquefaciens WS-8 by Pacific Biosciences RSII (PacBio) Single Molecule Real-Time (SMRT) sequencing. The genome consists of one chromosome (3,929,787 bp) and no additional plasmids. The main bacteriostatic substances were determined by genome, transcriptome, and mass spectrometry data. We thereby laid a theoretical foundation for the utilization of the strain. By genomic analysis, we identified 19 putative biosynthetic gene clusters for secondary metabolites, most of which are potentially involved in the biosynthesis of numerous bioactive metabolites, including difficidin, fengycin, and surfactin. Furthermore, a potential class II lanthipeptide biosynthetic gene cluster and genes that are involved in auxin biosynthesis were found. Through the analysis of transcriptome data, we found that the key bacteriostatic genes, as predicted in the genome, exhibited different levels of mRNA expression. Through metabolite isolation, purification, and exposure experiments, we found that a variety of metabolites of WS-8 exert an inhibitory effect on the necrotrophic fungus Botrytis cinerea, which causes gray mold; by mass spectrometry, we found that the main substances are mainly iturins and fengycins. Therefore, this strain has the potential to be utilized as an antifungal agent in agriculture.

• 치위생과학회지
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• 제18권1호
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• pp.18-23
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• 2018

Propolis has been used as a natural remedy in folk medicine worldwide. The antibacterial, antiviral, antifungal, and antiprotozoal aspects of its antimicrobial properties have been widely investigated. However, few studies focused on its applications in dentistry. Many dental diseases are related to various microorganisms in the oral cavity. In this study, we assessed the antimicrobial activity of Korean propolis extract, collected from 6 different regions, on oral pathogenic microorganisms. The propolis samples, collected from 6 different regions (P1: Uijeongbu, P2: Ansan, P3: Hongcheon, P4: Iksan, P5: Gwangju, and P6: Sangju), were dissolved in ethanol at two different concentrations (10 and 50 mg/ml). Three oral bacteria (Streptococcus mutans, Staphylococcus aureus, and Enterococcus faecalis) and one fungus (Candida albicans) were activated in general broth for 24 hours. Microorganisms were diluted and spread onto agar plates, onto which sterilized 6 mm filter papers with or without each propolis sample were placed. After 24 hours of incubation, clear zones of inhibition were observed. All tests were performed in triplicate. The propolis samples showed significant antibacterial and antifungal activity on oral pathogenic microorganisms; in addition, low-concentration groups showed outstanding antimicrobial efficacy on the 4 different microorganisms. Among the samples, P6 had significantly higher antibacterial activity than that of the others against three different bacteria. In particular, a high concentration of P6 showed a significant antifungal effect. In conclusion, we confirmed that Korean propolis has an inhibitory effect on oral pathogenic bacteria and fungi. Therefore, we suggest the possibility of developing oral medicine and oral care products based on Korean propolis.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.296-304
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• 1994

Antibiotic substances were produced by Bacillus subtilis YB-70, a potential biocontrol agent found to suppress root-rot of eggplant (Solanum melonggena L) caused by Fusarium solani, in a dextrose glutamate medium and isolated by isoelectric precipitation. Partial purification was performed by column chromatography on silica gel with two solvent systems: chloroform-methanol and methanol-chloroform-water as eluting solvents, This active fraction YBS-1 s contained antifungal activity were soluble in ethanol, methanol, and water, but were not soluble in other solvents including acetone, butanol, ethyl ether, dimethylformamide, propanol, and etc. High performance liquid chromatography and thin layer chromatographic separation of YBS-1s showed that they have been composed of three biological active bands that were named YBS-1A, -1B, and -1C. The substances were stable to heat and resistant to protease. YBS-1s were active against a wide range of plant pathogenic fungi but did not inhibit the growth of bacteria and yeasts. They were not only fungicidal but also fungistatic against chlamydospores of F. solani. The $ED_{50}$ values for the chlamydospore germination and the germ-tube growth of F. solani were $O.725\mu\textrm{m}/ml\;and\;O.562\mu\textrm{m}/ml$, respectively. Microscopic observations proved the substances restricted the growth of phytopathogenic fungus F. solani by spore burst followed by dissolving of its germ-tube, and caused abnormal hyphal swelling after application to chlamydospores or growing hyphae. Cultural filtrate of B; subtilis YB-70 also suppressed the development of root-rot of eggplant in pot tests.

• Journal of the Korean Wood Science and Technology
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• 제47권4호
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• pp.459-471
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• 2019

Several species of Aquilaria and Gyrinops are native to Indonesia and well known as agarwood-producing trees with a high economic value. Their bioactive compounds have a wide spectrum of uses, such as in medicine and cosmetics. These genera have undergone extensive search for novel bioactive compounds. The purpose of this study was to isolate, identify, and characterize the endophytic fungi community associated with Aquilaria malaccensis, A. microcarpa, Gyrinops versteegii, and A. crassna trees and investigate their bioactive properties as antioxidant agents and antagonists. A total of 50 fungi were successfully isolated from different tissues of the four species of agarwood-producing trees. Two isolates exhibited strong antioxidant activity, namely, Apodus oryzae (R2MC3A, $IC_{50}$ 60.92 mg/mL) and Diaporthe sp. (P1DS1[C], $IC_{50}$ 76.65 mg/mL). Two isolates, Pestalotiopsis theae (P3BS3[B]) and Curvularia sp. (P2CD3A), showed >75% antifungal activity against pathogenic Fusarium solani. The results revealed that endophytic fungi associated with the studied agarwood-producing trees had potential antioxidant and antifungal activities for further applications in biotechnology.

• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1696-1700
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• 2016

In order to discover plant-derived signaling pathway inhibitors with antifungal properties, a two-component screening system utilizing the calcineurin and Hog1 mitogen-activated protein kinase pathways responsible for the virulence networks of Cryptococcus neoformans was employed, owing to the counter-regulatory actions of these pathways. Of the 1,000 plant extracts tested, two bioactive compounds from Miliusa sinensis were found to act specifically on the calcineurin pathway of C. neoformans. These compounds, identified as pashanone and 5-hydroxy-6,7-dimethoxyflavanone, exhibited potent antifungal activities against various human pathogenic fungi with minimum inhibitory concentration values ranging from 4.0 to >128 μg/ml.

• KSBB Journal
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• 제32권2호
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• pp.146-152
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• 2017

Vulvovaginal candidiasis (VVC) is one of the urogenital infections occurring in women worldwide. Candida albicans is generally observed among various types of microorganisms causing VVC. Antibiotic therapy is typical, and the use of Lactobacilli probiotics is to be recognized as a promising alternative. The aim of this study was to select vaginal lactobacilli with probiotic properties against C. albicans. In a previous study, we isolated 38 lactobacilli from vagina of Korean women and 20 isolates were shown to inhibit C. albicans. We further selected 10 isolates which were able to inhibit C. albicans less than $10^5CFU/mL$. Among these selected strains, Lactobacillus salivarius MG242 (identified by 16s rRNA sequencing) was finally selected based on its strong anti-candidal activity, acid/bile salt resistance and adhesion property. Indirect adhesion activity of MG242 measured by auto-aggregation assay showed more than 60% auto-aggregation after 5 h standing. Taken these results together, the selected strain MG242 may have potential for application in vagina health related products.

• 한국미생물·생명공학회지
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• 제21권1호
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• pp.59-65
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• 1993

방선균 분리주 GMT 1153로부터 ts/NRK 세포의 형태를 변형된 세포형태에서 정상세포의 형태로 전환하는 활성물질을 분리, 정제하였다. 활성물질 MT 1155는 UV, IR, 1H-NMR, 13C-NMR, mass,원소분석 등의 기기분석을 통하여 항진균성 항암물질인 toyocamycin으로 동정되었다. MT 1155는 ts/NRK 세포의 형태전환에 대한 활성외에도 PKA 효소활성 저해와 CTLL 세포에 대한 세포독성이 있으나 K562 소포형성 억제 및 PKC 효소활성에 대한 저해효과도 없었다.