• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.469-474
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• 2001

The actinomycete strain AMLK-335 was antagonistic to vancomycin-resistant enterococci (VRE). Based on the diaminopimelic acid (DAP) type, and morphological and physiological characteristics revealed by scanning electron microscopy (SEM), AMLK-335 was confirmed to belong to the genus Streptomyces. Analysis of the 16S rDNA nucleotide sequences found AMLK-335 to have a relationship with Streptomyces platensis. The production of antibiotic from this strain was most favorable when cultured on glucose, polypeptone, yeast extract (PY) medium for 6 days at $27^{\circ}$. The antibiotic was identified as cyclo(L-phenylalanyl-L-prolyl) by comparing ti with the reported MS and NMR spectral data. Cyclo(phe-pro) from the PY cultures of AMLK-335 was most effective (K-98-258). Futhermore, cyclo(phe-pro) had antimicrobial activity against Bacillus subtilis, Microcuccs luteus, Staphylococcus aureus, and Saccharomyces cerevisiae, but it wa ineffective against Candida albicans, Streptomyces murinus, and Aspergillus niger.

• KSBB Journal
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• 제21권6호
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• pp.456-460
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• 2006

효소는 환경과 조건에 따라 상이한 활성도를 나타내며, 전기 자극에 의하여 비활성화된 알콜 산화효소는 당, 계면활성제, 히드로젤 들에 의하여 안정화되었다. 이들 효소는 trehalose, TritonX-100, Brij에서 보다 안정하였으며, 이들 효소의 안정도는 Hansenula sp., P. pastoris, C. boidinii에서 분리된 효소가 순서적으로 보다 안정하였다. 전기자극하에서 효소의 안정화에 대한 이 연구는 생물공학, 단백질공학, 의료공학 분야에 널리 이용될 수 있으리라 사료된다.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.434-437
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• 2005

During the screening for the inhibitors of cellulose biosynthesis as herbicides, we discovered a Streptomyces sp. A6497 with a selective antifungal activity against cellulose containing Phytophthora parasitica, but not against cellulose lacking Candida albicans. The inhibitor was isolated and identified, using a series of chromatographies. Based on structure analyses with UV spectrophotometry, mass and various NMR, the inhibitor was identified as sangivamycin. The compound exhibited strong antifungal activities against P. parasitica (MIC; 3.125 $\mu$g/ml). In particular, it showed strong herbicidal activities against various weeds in the greenhouse experiment. Taken together, these results suggest that sangivamycin is a useful lead compound for the development of new herbicides.

• 한국미생물·생명공학회지
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• 제37권1호
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• pp.42-48
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• 2009

본 연구에서는 여성의 질염을 일으키는 칸디다증 병원균에 대한 항진균 성분을 한약재에서 조사하였다. 한약재에 ethanol을 이용하여 phenol 성분을 추출하고, 추출물의 phenol 함량을 출정하였다. Ethanol농도에 따른 phenol성 물질의 용출량은 시료마다 다른 양상을 보이고 있는데, 40% ethanol 농도에서 가장 높은 용출량은 어성초, 지모, 금은화 등이며, 60% ethanol에서 가장 높은 용출량은 포공영, 작약 등이다. 황련은 80% ethanol 농도에서는 낮은 용출량을 보이나 다른 농도에서는 비슷한 용출량을 보이고 있고, 연교는 80% ethanol에서 높은 용출량을 보였다. 전자공여능은 ethanol 농도별 추출물에 따라 다르게 나타나고 있는데, 포공영은 80% ethanol 추출물 이상에서 전자공여 능을 보이며, 황련, 지모, 금은화는 100%의 ethanol추출물에서 전자공여능을 보였다. 한약재 추출물의 항균활성은 C. albicans는 황련 추출물 $200{\mu}g/mL$농도로 주입하였을 때 3mm의 저해환을 나타내었으며, C. tropicalis는 포공영 추출물을 $200{\mu}g/mL$ 농도로 주입시 2mm, 어성초 추출물을 $200{\mu}g/mL$ 농도로 주입시 2mm, 작약 추출물을 $200{\mu}g/mL$ 주입시 3 mm 저해환을 나타내었다. 황련 추출물은 50, 100, 150, $200{\mu}g/mL$ 농도로 주입시 2, 3, 6, 9mm의 저해환을 나타내었다. 추출물을 이용한 C. glabrata, C. parapsilesis, C. utils 3개 종에 대한 항균활성은 나타나지 않았다. 황련 추출물에서 항균성분은 TLC와 HPLC 분석을 통하여 berberin인 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.996-1006
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• 2019

Objective: This study aimed to gain deeper insights into the dynamic changes in spoilage fungi populations during fermentation and the influence of traditional additives on silage quality. Methods: Elephant grass (Pennisetum purpureum) was prepared without any additive (control), and with the addition of 0.5% salt, and 0.5% salt-0.2% sugar mixture. The fungal community was then determined using a classic culturing method and high-throughput sequencing at 0, 5, 15, and 60 days after ensiling. Results: The results showed that the fungal community of elephant grass silage varied significantly between the natural fermentation without any additive and the two additive groups. The diversity and relative abundance of spoilage molds in the control group were much higher than those in the two treatment groups (p<0.05). Three species of yeasts (Candida sp., Pichia sp., Trichosporon sp.) and four spoilage molds (Fusarium sp., Aspergillus sp., Muco sp. and Penicillin sp.) were the predominant fungi in elephant grass during natural fermentation from 0 to 60 days, which were found to be significantly decreased in salt and sugar additive groups (p<0.05). Meanwhile, the diversity and relative abundance of undesirable molds in the 0.5%-salt additive group were the lowest among all groups. Conclusion: Adding salt and sugar, particularly 0.5% salt, is a promising effective approach to reduce the amount of undesirable fungi thus, improving the silage quality of elephant grass in northern Vietnam.

• Journal of Microbiology and Biotechnology
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• 제28권1호
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• pp.105-108
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• 2018

Beef was dry aged for 40-60 days under controlled environmental conditions in a refrigerated room with a relative humidity of 75%-80% and air-flow. To date, there is little information on the microbial diversity and characteristics of dry aged beef. In this study, we explored the effect of change in meat microorganisms on dry aged beef. Initially, the total bacteria and LAB were significantly increased for 50 days during all dry aging periods. There was an absence of representative foodborne pathogens as well as coliforms. Interestingly, fungi including yeast and mold that possess specific features were observed during the dry aging period. The 5.8S rRNA sequencing results showed that potentially harmful yeasts/molds (Candida sp., Cladosporium sp., Rhodotorula sp.) were present at the initial point of dry aging and they disappeared with increasing dry aging time. Interestingly, Penicillium camemberti and Debaryomyces hansenii used for cheese manufacturing were observed with an increase in the dry aging period. Taken together, our results showed that the change in microorganisms exerts an influence on the quality and safety of dry aged beef, and our study identified that fungi may play an important role in the palatability and flavor development of dry aged beef.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.1006-1009
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• 2002

The biological activities of farnesoic acid derivatives against pathogenic fungi and bacteria were investigated. Farnesoic acid and its derivatives showed growth inhibitory activities against various bacteria. Among the compounds tested, geranylgeranoic acid (3) had potent antibacterial activity against Salmonella typhimurium, Proteus vulgaris, and Bacillus subtilis with minimum inhibitory concentration (MIC) in the range of $6.25-12.5{\mu}g/ml$. On the other hand, amide derivatives of farnesoic acid showed some antifungal activities. In particular, 3,7,11-trimethyl-dodeca-2,6,10-trienoic acid amide (5a) had a potent antifungal activity against Aspergillus niger, Candida albicans, and Trichophyton sp. with MIC in the range of $6.25-12.5{\mu}g/ml$.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2003년도 춘계총회 및 제22차 학술발표회
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• pp.104.2-105
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• 2003

Plant steryl esters have good effects on plasma cholesterol level and are used as functional food ingredient. Conjugated linoleic acid (CLA) presents mainly in animal foods and has a good benefit and medium chain fatty acids (MCFAs) are a rapid energy source for human. In this study, we produced the ${\beta}$-sitosterol esters from CLA and MCFAs using various lipases as catalysts. Among lipases, AYS (from Candida rugosa) was the most effective for synthesis of ${\beta}$-sitosterol esters in the presence of water (24.35% conversion) or hexane (25.33% conversion). The second esterification extent was obtained by lipase AK (from Pseudomonas sp), showing 10.26% conversion in water and 15.94% conversion in hexane, respectively. The reaction condition was 1:3 molar ratio (${\beta}$-sitosterol:fatty acid, 1:3) and stirred (175 rpm) at 55$^{\circ}C$ in water bath shaker for 48h.

• The Plant Pathology Journal
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• 제25권2호
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• pp.199-204
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• 2009

Three plant growth-promoting yeasts and two rhizobacteria were tested for controlling tomato wilt caused by Fusarium oxysporum f. sp. lycopersici under green-house and field conditions. Under greenhouse and field conditions, all treatments were significantly reduced disease severity of tomato wilt relative to the infected control. The highest disease reductions in pots (75.0, 67.4%) and field (52.5, 42.4%) were achieved by Azospirillum brasilense and Bacillus subtilis compared to infected control. Under field condition all treatments produced the highest tomato yield compared to the control plants inoculated with the pathogen.

• 농약과학회지
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• 제2권3호
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• pp.28-35
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• 1998

전국에서 분리한 세균으로부터 항균력이 있는 길항세균들을 먼저 분리한 다음 그중 배양배지 속으로 강력한 항균력을 나타내는 peptide를 분비하는 A405균주를 선발, Biolog System 및 rDNA 염기서열을 이용하여 Bacillus subtilis로 동정하고 이 균주가 생성하는 항균 peptide의 항균력을 조사한 바 Botrytis cinerea, Cercospora sp., Fusarium oxysporum, Penicillium digitatum, Celletotrichum gloeosporioides, Rhizoctonia solani, Pythium ultimum, Pyricularia oryzae등의 식물병원균과 Escherichia coli, Pseudomonas spp. 등의 세균 및 효모인 Candida albicans의 성장도 억제하는 강력한 항균력을 보였다. 또한 이 균주가 생산하는 항균 peptide는 알콜, 아세톤과 같은 유기용매에 내성을 가지고 있었으며 proteinase K와 phenol 처리시에는 항균력이 감소되거나 소실되는 특성을 가지고 있었다. 이 항균 peptide를 SDS-PAGE, Native-PAGE 및 Tris-Tricine 전기영동으로 분자량이 3kDa인 작은 peptide임을 확인하였고 aspartic acid, glycine, serine, glutamine, valine, leucine, isoleucine, proline, tyrocine 등의 9가지 아미노산으로 구성되어 있음을 Amino Acid Analyzer로 확인하였으며 냉동건조한 항균 peptide 50 ug/ml을 체리토마토에 처리하여 과일의 선도유지를 조사한 결과 대조구에 비하여 월등한 선도유지 효과가 있음을 입증하였다.