• Journal of Applied Biological Chemistry
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• 제62권4호
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• pp.385-389
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• 2019

본 연구에서는 홍삼 추출물 제조과정에서 추출 수율을 향상시킬 수 있는 효소를 선별하고 최적의 반응조건을 조사하였다. 상업용 단백질 분해효소 중 Alcalase가 단백질과 탄수화물 수율 향상에 효과적이었으며, 효소 사용량은 홍삼 중량의 2%, 반응 시간은 1.5시간이 적당하였다. 최적의 반응조건으로 홍삼을 Alcalase로 처리한 결과 대조구보다 고형분 수율은 45.1%에서 71.1%로 50% 이상, 총페놀 함량은 0.44%에서 0.80%로 80% 이상 증가하였으며, 항산화 활성은 대조군과 매우 유사하였다. 또한 진세노사이드 함량은 대조구의 1.48 mg/g에서 1.98 mg/g으로 30% 이상 증가하였다.

• Food Science and Biotechnology
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• 제14권1호
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• pp.49-57
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• 2005

Enterococcus faecium MJ-14, having strong antilisterial activity, was isolated from Korean fermented food, Meju. MJ-14 showed the same phenotypic characteristics, but different sugar utilization, as reference strain, E. faecium KCCM12118. It could utilize D-xylose, amygdaline, and gluconate, whereas E. faecium KCCM12118 could not. Optimal condition for bacteriocin production by E. faecium MJ-14 was at $37^{\circ}C$ and pH 7.0. Bacteriocin activity appeared in mid exponential phase and increased rapidly up to stationary phase. Activity was significantly promoted in MRS broth containing 3.0% glucose, 1.5% lactose, 2.0% peptone, or 1.5% tryptone. Bacteriocins effectively inhibited Enterococcus faecalis and Listeria spp. of Gram-positive bacteria, and Helicobacter pylori of Gram-negative bacteria, but did not inhibit yeasts and molds. They were stable against heat (for 30 min at $100^{\circ}C$), pH (3.0-9.0), long-term storage (for 60 days at 4 or $-20^{\circ}C$), and enzymatic digestion by catalase, proteinase K, papain, lysozyme, trypsin, chymotrypsin, and lipase, etc. Bacteriocin activity was completely inhibited by protease and pepsin, and 50% by ${\alpha}$-amylase. Studies on PCR detection of enterocin structural genes revealed bacteriocins are identical to enterocins A and B.

• Journal of Ginseng Research
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• 제34권4호
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• pp.321-326
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• 2010

Enzymatic treatment conditions for red ginseng residue (RGR) were investigated to apply RGR as a microbial medium. Polysaccharide hydrolyase and protease were screened to obtain high solid and carbohydrate yields, and a good degree of carbohydrate hydrolysis. The optimal dosage and reaction time for Viscozyme, the chosen polysaccharide hydrolyase, were found to be 1.0% (w/w) and 3 h, respectively. Of the tested proteases, Flavourzyme, whose optimal dosage was 0.5% (w/w), was selected. Co-treatment with the optimal dosages of Flavourzyme and Viscozyme increased solid yield, carbohydrate yield, and degree of carbohydrate hydrolysis by 76%, 65%, and 1,865%, respectively, over levels in non-treated RGR. The culture characteristics of Leuconostoc mesenteroides strain KACC 91459P grown in enzymatically hydrolyzed red ginseng residue (ERGR) and RGR suspensions were compared. After cultivation for 6 h, the viable cell counts of both cell suspensions rapidly increased to $1.3{\times}10^9$ colony-forming units (CFU)/g. Moreover, while the viable cell population drastically decreased to $2.4{\times}10^6\;CFU/g$ for cells grown in RGR medium, it was maintained in cells fermented in ERGR medium for 24 h.

• 대한수의학회지
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• 제26권2호
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• pp.251-257
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• 1986

Isolation of Staphylococcus hyicus subsp. hyicus from piglets suffering from exudative epidermitis and healthy pigs was performed, and some properties of the isolates were examined. Twentry-six litters of exudative epidermitis observed in the field were sucking piglets with ages ranging from 1 to 5 weeks and most (73.1%) of these cases occurred in piglets between 2 and 3 weeks of age. Staphylococcus hyicus subsp. hyicus was isolated front 192(38.9%) of 494 healthy pigs. The rate of isolation of these organism from healthy pigs was found to vary greatly among farms at an isolation rate of 33.3% to 45.5% and this organism was isolated more frequently front sucking piglets below the age of 8 weeks than adult pigs. All of the isolates originated from the diseased and healthy pigs were positive in heat-stable DNase, Tween 80 hydrolysis, gelatinase, protease, but negative in clumping factor and hemelysin on sheep blood agar. There was no difference related to origin in the production of extracellular active substances. Typical lesions of the classic exudative epidermitis were produced by inoculation of Staphylococcus hyicus subsp. hyicus isolated from the diseased and healthy pigs. The pathogenic potentials of isolates from healthy pigs were no different from that of the isolates obtained from diseased pigs.

• 한국미생물·생명공학회지
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• 제20권3호
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• pp.257-262
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• 1992

Streptomyces virginiae가 생산하는 virginimycin 생산 유도인자(virginiae butanolide C,VB-C) 결합 단백질의 ligand(VB-C)와의 결합활성에 미치는 일반적인 성질을 검토한 결과, 본 VB-C 결합단백질은 막성분을 제외한 세포질에 90% 이상 존재하며, 최적 pH는 7.0인 것으로 입증되었다. KCL 존재하 약 15%의 결합활성이 증대되었으며,$Mo^{6+}$ 이온 존재시 60%의 결합활성 저하를 보였다.

• 농업과학연구
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• 제41권3호
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• pp.237-243
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• 2014

Human Glucagon like peptide-1 (GLP-1) is an incretin hormone that promotes secretion of insulin. In order to eliminate the formation of the soluble aggregate, Ala19 in GLP-1 was substituted with Thr, resulting in a GLP-1 mutant GLP-1A19T. The gene synthesis of GLP-1A19T and the fusion of 6-lysine tagged ubiquitin gene were accomplished by using the overlap extension polymerase chain reaction. The ubiquitin fused GLP-1A19T (K6UbGLP-1A19T) is expressed as form of inclusion body with little formation of the soluble aggregation in recombinant E. coli. In order to produce K6UbGLP-1A19T in large amounts, fed-batch fermentation was carried out in a pH-stat feeding strategy. Maximum dry cell weight of 87.7 g/L and 20.4% of specific K6UbGLP-1A19T content were obtained. Solid-phase refolding using a cation exchanger was carried out to renature K6UbGLP-1A19T. The refolded K6UbGLP-1A19T aggregated little and was released GLP-1A19T by on-column cleavage with ubiquitin-specific protease-1. The molecular mass of GLP-1A19T showed an accurate agreement with its theoretical molecular mass.

• 한국산학기술학회논문지
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• 제5권4호
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• pp.345-349
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• 2004

본 연구는 녹차추출물을 함유하는 녹차청국장의 제조방법에 관한 것이다. 단백질 분해효소 활성이 높은 균주를 분리 동정하여 Bacillus sp. Bl으로 명명하고 이를 청국장 제조에 사용하였다. Bacillus sp. Bl를 사용하여 청국장을 제조함에 있어서 0.2% 농도의 녹차추출액을 대두중량 대비 1.25%, 2.5%, 5% 첨가하여 청국장을 발효시켰다. 녹차추출액(TS 0.2%)을 1.25% 첨가하여 청국장을 발효시키는 것이 미생물 생육과 관능평가에 있어서 가장 우수한 것으로 나타났다. 휘발성 향기성분 분석에서 청국장 발효에 녹차추출물의 첨가는 불쾌취 발생을 억제하는 데 효과를 보였다.

• 한국산학기술학회논문지
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• 제6권4호
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• pp.342-348
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• 2005

본 연구에서는 음식물쓰레기 중의 단백질 분해활성을 갖는 대사산물을 생산하는 신규 바실러스 속 PNV-1 균주를 분리하였고, 분리된 균주를 이용하여 한국형 음식물쓰레기 환경인 고염분, 극한 pH, 고농도의 미생물 생육 저해물질 등에 대한 내성정도를 측정하였다. 실험 결과, 분리된 바실러스 속 균주는 약 0.68 unit/ml 이상의 높은 단백질분해효소 활성을 보유하고 있으며, 음식물쓰레기 중에 형성되는 pH 4 내지 9 범위에서 생육이 가능하고, 염분농도 최고 $8\%$와 살균작용을 하는 것으로 알려진 고춧가루 $5\%$에서도 생육에 거의 영향이 없었다. 또한, 미생물 생육 저해물질로 알려진 후추와 겨자에 대한 내성을 나타내었다.

• 한국식품영양과학회지
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• 제30권5호
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• pp.888-893
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• 2001

Soy sauce has a long history used as a food ingredient. However, hydrolyzed vegetable protein, mono-sodium glutamate, starch syrup, and fructose are added to soy sauce during fermentation for the taste and flavor of product. But consumers have been reluctant to the taste of these artificial additives. In this experiment, anchovy sauce was used to prepare soy sauce to enhance the quality and brine was used as a control. To evaluate the quality of soy sauce added with anchovy, total nitrogen (TN) and soluble nitrogen contents, total soild contents, total sugar reducing sugar. lactic acid content and protease activity were monitored during fer-mentation. Total microbial numbers and lactic acid bacteria were not significantly changed among the cases. Aerobic and anaerobic microorganisms. and lactic acid bacteria were not significantly changed among the cases we studied, For the total sensory test, it was also estimated that the cases using anchovy sauce were superior to the control. From the results mentioned above, we could obtain shorter fermenation period as well as the quality improvement in the case of using anchovy sauce instead of salty water in the fermented soy sauce production.

• 한국축산식품학회지
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• 제38권6호
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• pp.1315-1321
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• 2018

Bacteriocin is ribosomally synthesized by bacteria and inhibits closely related species. In this study we aimed at isolating lactic acid bacteria producing bacteriocin presenting anti-staphylococcal activity. A Lactococcus lactis strain was isolated from kimchi for the purpose and identified by 16S rRNA gene sequencing. As preliminary tests, optimal culture conditions, stabilities against heat, solvents, and enzymes treatments, and type of action (bacteriostatic or bactericidal) of the bacteriocin were investigated. The optimal culture conditions for production of the bacteriocin were MRS broth medium and $25^{\circ}C$ and $30^{\circ}C$ culture temperatures. The bacteriocin was acidic and the activity was abolished by a protease treatment. Its stability was maintained at $100^{\circ}C$ for 15 min and under treatments of various organic solvents such as methanol, ethanol, acetone, acetonitrile, and chloroform. Finally, the bacteriocin showed bactericidal action against Staphylococcus aureus where 200 AU/mL of the bacteriocin decreased the viable cell count (CFU/mL) of S. aureus by 2.5 log scale, compared with a control (no bacteriocin added) after 4-h incubation.