• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.349-354
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• 2006

Furaneol, a key aroma compound found in strawberry, pineapple, and processed foodstuffs, has been known to possess various biological activities on animal models. In this study, the antimicrobial effects of furaneol against human pathogenic microorganisms were investigated. The results indicated that furaneol displayed a broad spectrum of antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi without hemolytic activity on human erythrocyte cells. To confirm the antifungal activity of furaneol, we examined the accumulation of intracellular trehalose as a stress response marker on toxic agents and its effect on dimorphic transition of Candida albicans. The results demonstrated that furaneol induced significant accumulation of intracellular trehalose and exerted its antifungal effect by disrupting serum-induced mycelial forms. These results suggest that furaneol could be a therapeutic agent having a broad spectrum of antimicrobial activity on human pathogenic microorganisms.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1226-1231
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• 2014

The rare actinomycete Pseudonocardia autotrophica was previously shown to produce a solubility-improved toxicity-reduced novel polyene compound named $\underline{N}ystatin$-like $\underline{P}seudonocardia$ $\underline{P}olyene$ (NPP). The low productivity of NPP in P. autotrophica implies that its biosynthetic pathway is tightly regulated. In this study, $wblA_{pau}$ was isolated and identified as a novel negative regulatory gene for NPP production in P. autotrophica, which showed approximately 49% amino acid identity with a global antibiotic down-regulatory gene, wblA, identified from various Streptomycetes species. Although no significant difference in NPP production was observed between P. autotrophica harboring empty vector and the S. coelicolor wblA under its native promoter, approximately 12% less NPP was produced in P. autotrophica expressing the wblA gene under the strong constitutive $ermE^*$ promoter. Furthermore, disruption of the $wblA_{pau}$ gene from P. autotrophica resulted in an approximately 80% increase in NPP productivity. These results strongly suggest that identification and inactivation of the global antibiotic down-regulatory gene wblA ortholog are a critical strategy for improving secondary metabolite overproduction in not only Streptomyces but also non-Streptomyces rare actinomycete species.

• The Plant Pathology Journal
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• 제23권3호
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• pp.180-186
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• 2007

The biocontrol agent, Serratia plymuthica A21-4, has been developed for controlling pepper Phytophthora blight. Serratia plymuthica A21-4 strongly inhibits the mycelial growth, zoospore formation, and cyst germination of Phytophthora capsici in vitro. The application of a cell suspension of strain A21-4 to pepper plants in pot experiments and in greenhouse successfully controlled the disease. The bacteria produced a potent antifungal substance which was a key factor in the suppression of Phytophthora capsici. The most active chemical com-pound was isolated and purified by antifungal activity-guided fractionation. The chemical structure was identified as a chlorinated macrolide $(C_{23}H_{31}O_8Cl)$ by spectroscopic (UV, IR, MS, and NMR) data, and was named macrocyclic lactone A21-4. The active compound significantly inhibited the formation of zoosporangia and zoospore and germination of cyst of P. capsici at concentrations lower than $0.0625{\mu}g/ml$. The effective concentrations of the macrocyclic lactone A21-4 for $ED_{50}$ of mycelial growth inhibition were $0.25{\mu}g/ml,\;0.25{\mu}g/ml,\;0.30{\mu}g/ml \;and\;0.75{\mu}g/ml$ against P. capsici, Pythium ultimum, Sclerotinia sclerotiorum and Botrytis cinerea, respectively.

• Applied Biological Chemistry
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• 제40권2호
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• pp.139-143
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• 1997

새로운 살균제를 개발할 목적으로 2-이미노티아졸린 유도체를 합성하여 그 생물활성을 시험하였다. 1차아민과 이소티오시아네이트를 결합시켜 티오우레아 유도체를 제조한 다음 이것을 클로로아세트알데히드 또는 알파-할로케토산과 반응시켜 새로운 36종의 2-이미노티아졸린 유도체를 합성하였으며 이들의 6가지 중요한 식물병원균에 대한 항균력을 조사한 결과 티아졸린의 C-2 위치에 페닐이미노기, C-3 위치에 메틸, C-4 위치에 페닐카바모일메틸기, 그리고 C-5위치에 수소원자가 있을 때 벼 도열병균(Pyriculraria oryzae, rice blast)에 대한 항균활성이 가장 높았다.

• 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.

• 식품보건융합연구
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• 제6권3호
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• pp.5-21
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• 2020

Bungkang (Syzygium polyanthum) is a medium to tall plant which produces medicinal root-bark, the plant is normally found along inland river bank and produces small white flowers and fruits. Essential oils are among the most interesting components of the plant extracts consisting mostly of monoterpenoid or sesquiterpenoids. They are used as therapeutic agents in ethno, conventional, and complementary alternative medicines. Investigation and evaluation of the essential oil of Syzygium polyanthum as well as the antibacterial, antioxidant and antifungal activity was ascertained. The experiment was performed. 100 chemical constituents were obtained and two pure compound was isolated as Eugenol (1) and Farnesol (2). Significant growth inhibition of Staphylococcus aureus, (ATCCⓒ25923) Klebsiellia pneumonia (ATCCⓒ19155), Salmonella typhi (ATCCⓒ14028) and Escherichia coli (ATCC©25922) and the fungal strains Aspergillus flavin, Aspergillus niger, Candida, tropicalis, and Fusarium oxysporium was observed from the essential oil at concentration of 500 ㎍/mL. Antioxidant potential was observed to be strong of 18.42 ㎍/mL when compared to the control of 15.23 ㎍/mL. The result indicated that the oil obtained from root-bark of Syzygium polyanthum can be considered as an agent for antioxidant, antibacterial and antifungal in pharmaceutical food and cosmetic industries trails.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.909-912
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• 2005

In the course of screening for selective growth inhibitors against the mycelial form of Candida albicans, we isolated a Streptomyces sp. A6792 from soils. The inhibitor was isolated from the above bacterium and identified through several spectral analyses with UV and mass spectrophotometries, and various NMR. The compound was determined to be a macrocyclic dilactone antibiotic, IKD-8344 (molecular weight: 844, molecular formula: $C_{48}H_{76}O_{12}$). The compound selectively inhibited the growth of mycelial form of C. albicans with an MIC of 6.25 ${\mu}g/ml$. It also exhibited strong inhibitory effect preferentially on the mycelial form of various Candida spp. including C. krusei, C. tropicalis, and C. lusitaniae, with MICs ranging from 1.56 to 25 ${\mu}g$/ml. Furthermore, the compound showed no significant toxicity against SPF ICR mice up to 60 mg/kg. These results suggest that IKD-8344 is a useful lead compound for the development of novel antifungal agents, based on the preferential growth inhibition against Candida spp.

• 한국버섯학회지
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• 제9권4호
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• pp.180-185
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• 2011

버섯 생산 후 발생되는 부산물인 새송이버섯 수확 후 배지로부터 surfactin을 생성하는 4종의 균주를 분리하였으며 이 중 곰팡이 독소를 생성하는 A. flavus와 A. ochraceous에 대한 항균활성이 우수한 균주를 최종 선발하여 YJ07로 명명하였다. Bacillus ID kit와 VITEK 2 system를 이용하여 분리균 YJ07의 생리적 생화학적 특성을 조사한 결과 분리균은 B. subtilis, B. amyloliquefaciens와 유사한 생리적 생화학적 특성을 나타내었으며 16S rDNA 염기서열 분석을 통한 계통학적 유연관계에서도 B. amyloliquefaciens와 99.5%의 상동성을 나타내었다. 이와 같은 결과를 종합하여 분리균 YJ07은 B. amyloliquefaciens YJ07로 동정되었으며 분리균 YJ07이 생성하는 항균물질은 TLC와 HPLC 분석에서 reference 물질로 사용한 srfactin과 유사한 특성을 나타내었다.

• 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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• 제18권9호
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• pp.1537-1543
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• 2008

We tested Trichoderma harzianum as a biocontrol agent for Rhizoctonia solani AG2-1, using six natural antifungal materials to improve its efficacy. Among the six materials tested, peony (Paeonia suffruticosa) root bark (PRB) showed the strongest antifungal activity against R. solani AG2-1, and was not antagonistic to T. harzianum. Scanning electron microscopy showed that treatment with PRB extract resulted in shortened and deformed R. so/ani AG2-1 hyphal cells. The control of radish damping-off caused by R. so/ani AG2-1 was greatly increased by combined treatments of T. harzianum and PRB, as compared with either of the two treatments alone, with the control effect increased from 42.3-51.5% to 71.4-87.6%. The antifungal compound in PRB, which was isolated in chloroform and identified as paeonol by mass spectrometry, $^1H$ NMR, and $^{13}C$ NMR analyses, inhibited the growth of R. so/ani AG2-1 but not that of T. harzianum. Thus, PRB powder or extract may be used as a safe additive to T. harzianum to improve the control of the soil borne diseases caused by R. so/ani AG2-1.