• Title/Summary/Keyword: natural yeast

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Fermentation of Acidic Beverage with Dropped Peach (복숭아 낙과를 이용한 초산음료의 발효)

  • 김순동;이재석;김미경
    • Journal of the East Asian Society of Dietary Life
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    • v.4 no.3
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    • pp.135-146
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    • 1994
  • The study was conducted to research the desirable method for fermentation of acidic beverage in the farmhouse using peach dropped at harvesting periods. Step by step fermentation(SSF), complex fermentation after crushing of the fruit(CCF), complex fermentation after slicing of the fruit(SCF) and natural fermenation added yeast only after slicing of the fruit(SYNF) were compared. The brief stationary fermentor for complex fermentation in the farmhouse was made in this experiment. The ability of acid production, flavor, taste and color were measured by sensory evaluation and mechanical methods. The quality of vinegar by SYNF was the most desirable, estimated by the color, the flavor, the content and composition of sugar, and of organic acids, and which was a suitable fermentation method for the farmhouse. The strains of acetobacter SYNF-1, 2 and 3 were isolated from the SYNF vinegar, and the SYNF-1 was a main strain.

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Expression of Antibacterial Cationic Peptides from Methylotrophic Yeast, Pichia pastoris

  • Lee, Gang-U;Choe, Yun-Jae
    • 한국생물공학회:학술대회논문집
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    • 2000.11a
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    • pp.669-671
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    • 2000
  • Antimicrobial cationic peptides have attracted increasing research and clinical interest as a natural antibiotics due to their broad spectrum of antimicrobial activites and the rapid development of multidrug-resistant pathogenic microorganisms. In this study, first, we synthesized artificial fusion partner and cationic peptide genes (lactoferricin, magainin, protegrin-1, and indolicidin). Second, we constructed recombinant expression vectors and then transformed Pichia pastoris. Finally, expressed cationic peptides were purified and tested for their antimicrobial activites. Antimicrobial activity has been tested upon the appearance of clearing zone on the plate with the lawn of gram negative E.coli XL- I blue and garm positive Staphylococcus aureus. Protegrin-1 and Indolicidin have apparant activity of cationic peotides. This fusion technique may lead to a general and suitable tool for production of pure antimicrobial cationic peptides in Pichia pastoris.

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Antilisterial Bacteriocin from Lactobacillus rhamnosus CJNU 0519 Presenting a Narrow Antimicrobial Spectrum

  • Jeong, Ye-Jin;Moon, Gi-Seong
    • Food Science of Animal Resources
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    • v.35 no.1
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    • pp.137-142
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    • 2015
  • A lactic acid bacterium presenting antimicrobial activity against a Lactobacillus acidophilus strain used for eradication of acid inhibition was isolated from a natural cheese. The 16S rRNA gene sequence of the isolate best matched with a strain of L. rhamnosus and was designated L. rhamnosus CJNU 0519. The antimicrobial activity of the partially purified bacteriocin of CJNU 0519 was abolished when treated with a protease, indicating the protein nature of the bacteriocin. The partially purified bacteriocin (rhamnocin 519) displayed a narrow antimicrobial activity against L. acidophilus, Listeria monocytogenes, and Staphylococcus aureus among several tested bacterial and yeast strains. Rhamnocin 519 in particular showed strong bactericidal action against L. monocytogenes.

Effects of Ozone Treatment and Gamma Irradiation on the Microbial Decontamination and Physicochemical Properties of Red Pepper Powder (고춧가루의 오염미생물 제거 및 이화확적 특성에 관한 오존처리와 감마선 조사의 영향)

  • 이성희;이현자;변명우
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.3
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    • pp.465-467
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    • 1997
  • The comparative effects of ozone treatment and gamma irradiation on the sterilization, physicochemical properties and sensory quality of red pepper powder were investigated. As for the sterilization of microorganisms, 7.5~10 KGy of gamma irradiation completely eliminated the coliforms, yeast and molds, and total aerobic bacteria. On the other hand, ozone treatment failed to eliminate the highly contaminated microbial load, especially total aerobic bacteria. The physicochemical properties including capsaicin, capsanthin, browning, fatty acid compositions and sensory quality were not significantly changed by gamma irradiation up to 10 kGy, whereas ozone treatment caused significant changes in fatty acid compositions and destruction of natural pigments (p<0.05). The above results led us to conclude that gamma irradiation was more effective than ozone treatment for the sterilization and maintenance of physicochemical and sensory qualities of red pepper powders.

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Antimicrobial and Cytotoxic Activities of Some Malaysian Flowering Plants

  • Jasril, Jasril;Mohamed, S.M.;Mackeen, M.M.;Lajis, N.H.;Rahman, A.A.;Ali, A.M.
    • Natural Product Sciences
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    • v.5 no.4
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    • pp.172-176
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    • 1999
  • A total of 43 extracts from 21 species of Malaysian flowering plants were screened for antimicrobial and cytotoxic activities. Antimicrobial activity was tested against fungi, including yeast and candida, as well as Gram-positive and Gram-negative bacteria, and cytotoxicity was assayed using the CEM-SS and HT-29 cell lines. The methanol extracts of the roots and stems of Plumeria acutifolia showed the highest antimicrobial activity, i.e. against Saccharomyces cerevisiae and Candida lipolytica, and mostly moderate activity against the other microbes such as Aspergillus ochraceous and Saccharomyces lipolytica. Phyllanthus emblica also showed moderate activity especially that of the methanol extracts. The methanol extract of the roots of Plumeria acutifolia showed the strongest cytotoxic activity $(CD_{50}=\;3\;{\mu}g/ml)$. Most of Zingiberaceae species gave negative results for antimicrobial activity and showed low cytotoxic activity.

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Isolation and Identification of the Amylolytic Yeast Hansenula and its Haploid Mutant (전분이용성 Hansenula의 분리동정 및 변리주 개발)

  • 구영조;박완수;신동화;유태종
    • Microbiology and Biotechnology Letters
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    • v.13 no.2
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    • pp.129-135
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    • 1985
  • The amylolytic yeasts were isolated from natural sources. Among them, a strain FRI YO-32 was selected as one of the genetically potential microorganisms and was identified as a strain of Hansenula anomala var anomala. Genetic markers were introduced into the isolated haploid strains of the strain FRI YO-32 and Saccharomyces cerevisiae by conventional mutagenic procedures with EMS or MNNG.

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Chemical Modification of Yeast Farnesyl Protein Transferase Expressed in E. coli

  • Kim, Hyun-Kyung;Yang, Chul-Hak
    • Bulletin of the Korean Chemical Society
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    • v.27 no.4
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    • pp.529-534
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    • 2006
  • Chemical modification of the S. cerevisiae farnesyl protein transferase (FPT) with CMC, phenylglyoxal and DEPC resulted in enzyme inactivation, depending upon the reagent concentration. The peptide substrate GST-PEP-I, a GST-fused undecapeptide mimicking the C-terminus of $p21^{Ki-ras}$, protected the enzyme against inactivation by CMC which is specific to either aspartate or glutamate, while the other substrate farnesyl pyrophosphate (FPP) showed protection against phenylglyoxal which is the specific modifier of arginine residues, dependent on the substrate concentrations. Neither of the two substrates protected the enzyme against histidine inactivation by DEPC. It is suggested that there is at least one aspartate or glutamate residue at the peptide substrate binding site, and that at least one arginine residue is located at the binding site of FPP. There also seems to be at least one histidine residue which is critical for enzymic activity and is exposed toward the bulk solution, excluded from the substrate binding sites.

한국산 야생효모에 관한 연구 3

  • 박명삼
    • Korean Journal of Microbiology
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    • v.10 no.2
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    • pp.51-68
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    • 1972
  • The aim of the sutdy is to collect a variety of wild yeasts from different regions in Korea and in different seasons and to account for the natural patterns of regional and seasonal variation that they display. From the specimens collected in this study, more useful strains are expected to be discovered, which can be cultivated and utilized fro industrial development. The study attempts to determine the degree to which utilizable yeasts can be applied in brewing, confectionary, baking, the manufacture of medicine, and as feed yeast. Such findings would contribute not only to the development of academic research, but would also be important in obtaining raw material that can be applied in our daily lives and in industrial development in response to the demands of the times.

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Conformational Study of Y-Base in Yeast tRNA$^{phe}$

  • Moon, Myung-Jun;Jhon, Mu-Shik;Kang, Young-Kee
    • Bulletin of the Korean Chemical Society
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    • v.4 no.3
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    • pp.133-139
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    • 1983
  • To understand the importance of Y-base adjacent to the anticodon stabilizing codon-anticodon interaction, a study has been undertaken for the model compound involving the interaction between Y-base and anticodon as well as the participation of water molecule by calculating the conformational free energy using an empirical potential function. We restrict our analysis to sites directly associated with Y-base by varying only the backbone torsion angles of Y-base. The hydration and $Mg^{+2}$ binding effects on the conformational stability of Y-base are calculated and discussed. The free Y-base is proved to be less stable than the hydrated one. The free energy change due to the hydration of Y-base amounts to -119.5 kcal/mole, in which the conformational energy change is -142.4 kcal/mole and the configurational entropy change is -76.9 e. u. It is found that the water molecules bound to Y-base and $Mg^{+2}$ contribute to the conformation of Y-base dominantly.