• Applied Biological Chemistry
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• 제19권3호
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• pp.155-161
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• 1976

종국(種麴)의 종류(種類)를 달리하여 제국(製麴)한것으로 담금하여 발효과정중(醱酵過程中)의 효소활성(酵素活性), 미생물균수(微生物菌數), 일반성분(一般成分), 질소용해율등(窒素溶解率等)의 변화(變化)에 대(對)하여 실험(實驗)한 결과(結果)는 다음과 같다. (1) 간장 발효중(醱酵中)의 중성(中性) 및 alkali성(性) protease의 활성(活性)은 발효기간(醱酵期間)의 경과(經過)에 따라 실활(失活)되였고 세균함유종국구(細菌含有種麴區)가 더욱 현저하였다. (2) 간장 발효중(醱酵中)의 미생물균수(微生物菌數)는 발효기간(醱酵期間)의 경과(經過)에 따라 각시험구(各試驗區) 모두 증가하는 경향을 나타났으며 특히 세균함유종국구(細菌含有種麴區)가 현저하였다. (3) 일반성분중(一般成分中) TN, amino-N. ammonia-N 등은 발효기간(醱酵期間)의 경과(經過)에 따라 증가하였으며 alcohol, 유리환원당, 순고형물(純固形物) 등은 발효초기(醱酵初期)에 다소 증가하다가 점차 감소하는 경향을 보였다. (4) 세균함유종국구(細菌含有種麴區)는 타시험구(他試驗區)에 비(比)하여 ammonia-N의 함량(含量)이 높았으나 pH는 낮은 편이였다. (5) 질소용해율(窒素溶解率) 및 관능검사의 결과(結果) 순수종국구(純粹種麴區)가 가장 좋았으며 세균함유종국구(細菌含有種麴區)가 가장 불량(不良)하였다.

• 한국식품과학회지
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• 제32권6호
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• pp.1350-1357
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• 2000

우수균주를 접종한 고추장에 항균성 물질을 함유하고 있는 양고추냉이와 겨자 분말을 첨가하여 $25^{\circ}C$에서 발효시키면서 미생물과 성분의 변화를 비교하였다. 향신료 첨가로 인해 고추장 효모의 증식이 억제됨으로서 유통중 문제가 되는 가스가 발생되지 않았고 세균수에는 큰 차이가 없었다. 아미노산성 질소는 발효가 진행되면서 계속하여 증가하였으며 발효 120일째 P-2 코지와 겨자 분말을 함께 첨가한 실험구의 함량이 유의적으로 높았다. 효소 역가의 경우 ${\alpha}-amylase$활성은 매우 낮았으나 ${\beta}-amylase$는 향신료 첨가구의 활성이 높았고, protease(산성, 중성)는 발효가 진행되면서 계속 증가하였으나 실험구간의 뚜렷한 차이는 보이지 않았다. 고추장의 색과 향기는 실험구간의 유의적 차이를 보이지 않았고 맛과 전체적 기호도의 경우 양고추냉이 첨가구와 P-2 코지만을 첨가한 실험구가 우수하였다. 양고추냉이 및 겨자를 첨가하고 선발된 균주를 이용하여 발효시킨 고추장은 저장 중 가스발생이 완전히 억제되었고 품질 또한 우수하였다.

• 한국식품과학회지
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• 제32권5호
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• pp.1051-1057
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• 2000

관능적 품질이 우수하고 저장성을 향상시킨 저염 새우젓 개발을 위해 감마선 조사기술을 이용하였다. 식염농도를 15% 및 20%로 조절한 새우젓을 제조하여 $15^{\circ}C$에서 발효시키면서, 최적 숙성기에 도달하기 직전 아미노태 질소의 함량이 400mg% 수준에서 5 kGy 및 10 kGy 선량의 감마선을 조사하였으며, 대조구로는 30% 식염농도의 새우젓을 제조하여 저장기간 동안 화학적 품질을 평가하였다. 최적 숙성직전 감마선을 조사한 결과, 감마선 조사직후 아미노태 질소, 휘발성 염기태 질소, trimethylamine 및 효소활성은 감마선 조사에 의한 영향은 나타나지 않았다. 저장기간에 따른 성분의 변화는 식염함량 및 감마선 조사선량이 증가할수록 낮았으며, 효소활성은 발효 4∼5주까지 계속 증가하다가 감소하는 경향으로 대조구와 유사한 활성을 나타내었다. 특히 15% 식염과 10 kGy의 감마선 조사 및 20% 식염과 5 kGy 이상의 감마선을 최적 숙성직전 조사한 새우젓의 경우 젓갈의 화학적 품질지표인 아미노태 질소, 휘발성 염기태 질소, trimethylamine 함량 및 단백질분해 효소활성이 30% 고염농도인 대조구와 비슷한 수준으로, 발효기간 동안 적정수준의 함량 및 활성을 나타내어 양호한 품질특성을 보였다.

• Journal of Microbiology and Biotechnology
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• 제14권3호
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• pp.503-508
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• 2004

The antimicrobial substance produced by Lactobacillus bulgaricus was inactivated by protease. It showed inhibitory activity against Staphylococcus aureus ATCC6538, Streptococcus agalactiae ATCC14364, some Gram-positive and Gram-negative bacteria, and characteristics of a bacteriocin. The optimal temperature and culture time for the production of bacteriocin were $30^{\circ}C$ and 10 h, respectively, in the culture of L. bulgaricus. The bacteriocin production started in the exponential phase and reached a maximum at the early stationary phase. Using Staph. aureus ATCC6538 and Strep. agalactiae ATCC14364, known as common bovine mastitis pathogens, as indicator strains for determination of the bacteriocin activity, the antimicrobial activity of the bacteriocin was found to be stable in acidic and neutral pH's (2- 7) even at lOOT, whereas it was lost at high pH (10- 11) and $100^{\circ}C$. The mode of action for the antimicrobial activity was bacteriocidal, and the molecular weight determined by SDS-PAGE and overlay method was 14 kDa.

• 한국미생물·생명공학회지
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• 제25권5호
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• pp.448-453
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• 1997

Enzyme activities, production of killer toxin and some functionality of forty seven yeasts isolated from traditional Meju were investigated in culture broth and cell free extracts. Activities of $\alpha$-galactosidase, invertase and inulinase were detected in cell free extracts of 38 strains, 43 strains and 45 strains, respectively and acidic and neutral protease activities also were detected in culture broth of all the strains, $\beta$-Galactosidase activity was detected in cell free extracts of OE-20 and S-14 strains. Killer toxins were produced by OE-12, S-8 (Candida spp.), OE-19 (Zygosaccharomyces spp.) and S-3 (Saccharomyces spp.). Culture broth of OE-23 and S-9 showed 61.3% and 59.2% of antioxidant activity to $\alpha$, $\alpha$-diphenyl-$\beta$-picrylhydrazyl(DPPH), but nitrite-scavenging ability as well as inhibition of tyrosinase and polyphenol oxidase were not appeared in all the strains.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.593-598
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• 2005

A collagenolytic enzyme, produced by Vibrio vulnificus CYK279H, was purified by ultrafiltration, dialysis, Q-Sepharose ion exchange and Superdex-200 gel chromatography. The enzyme from the supernatant was purified 13.2 fold, with a yield of 11.4%. The molecular weight of the purified enzyme was estimated by SDS-PAGE to be approximately 35.0kDa. The N-terminal sequence of the enzyme was determined as Gly-Asp-Pro-Cys-Met-Pro-Ile-Ile-Ser-Asn. The optimum temperature and pH for the enzyme activity were $35^{\circ}C$ and 7.5, respectively. The enzyme activity was stable within the pH and temperature ranges 6.8-8.0 and $20{\sim}35^{\circ}C$, respectively. The purified enzyme was strongly activated by $Zn^{2+},\;Li^{2+},\;and\;Ca^{2+}$, but inhibited by $Cu^{2+}$. In addition, the enzyme was strongly inhibited by 1, 10-phenanthroline and EDTA. The purified enzyme was suggested to be a neutral metalloprotease.

• Parasites, Hosts and Diseases
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• 제44권3호
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• pp.251-254
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• 2006

Monoclonal antibody (mAb) Tg786 against Toxoplasma gondii has been found to detect a 42-kDa rhoptry protein (ROP6) which showed protease activity and host cell binding characteristics after secretion. Using the mAb, a colony containing a 3'-UTR was probed in a T. gondii cDNA expression library. A full length cDNA sequence of the rhoptry protein was completed after 5'-RACE, which consisted of 1,908 bp with a 1,443 bp ORF. The deduced amino acid sequence of ROP6 consisted of a polypeptide of 480 amino acids without significant homology to any other known proteins. This sequence contains an amino terminal stop transfer sequence downstream of a short neutral sequence, hydrophilic middle sequence, and hydrophobic carboxy terminus. It is suggested that the ROP6 is inserted into the rhoptry membrane with both N- and C-termini.

• Parasites, Hosts and Diseases
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• 제41권3호
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• pp.165-169
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• 2003

This study describes the characterization of 80 kDa pretense showing gelationlytic property among three pretenses in the excretory/secretory proteins (ESP) from Toxoplasma gondii. The pretense activity was detected in the ESP but not in the somatic extract of RH tachyzoites. This pretense was active only in the presence of calcium ion but not other divalent cationic ions such as $Cu^{2+},{\;}Zn^{2+},{\;}Mg^{2+},{\;}and{\;}$Mn^{2+}$, implying that $Ca^{2+}$ is critical factor for the activation of the protease. The 80 kDa pretense was optimally active at pH 7.5. Its gelatinolytic activity was maximal at $37^{\circ}C$, and significant level of enzyme activity of the pretense remained after heat treatment at $56^{\circ}C$ for 30 min or $100^{\circ}C$ for 10 min, This thermostable enzyme was strongly inhibited by metal chelators, i.e., EDTA, EGTA, and 11 10-phenanthroline. Thus, the 80 kDa pretense in the ESP secreted by T. gondii was classified as a calcium dependent neutral metalloprotease.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.247-253
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• 1996

Changes in microorganisms, enzyme activities and major components of two types of Doenjang prepared with spring Meju and autumn Meju and Kochujang were investigated during 4 months of fermentation. The viable cell counts of aerobic bacteria in Doenjang and Kochujang were increased up to 60 days of fermentation, but viable cell counts of anaerobic bacteria did not show remarkable changes during fermentation. Viable cell count of yeast showed a rapid increase up to 15 days of fermentation in Doenjang and 60 days in Kochujang. It was found that $\alpha$-amylase activity of autumn Meju Doenjang and glucoamylase activity of Kochujang were higher than the other. Acidic and neutral protease showed the highest activity during 15-30 days of fermentation. The pH of Doenjang was increased up to pH 7.0 until 60 days of fermentation, but pH of Kochujang gradually decreased during fermentation. Moisture content of spring Meju Doenjang and Kochujang decreased to 40% during ferme- ntation and reducing sugar content of Kochujang increased up to 15 days of fermentation, but decreased after that.

• 한국식품영양학회지
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• 제7권2호
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• pp.151-158
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• 1994

This study was carried out to clear up the cause of low-acid producing phenomenon occurred In non-fat dry milk during liquid-yoghurt fermentation by Lactobacillus case, and to present its improving methods. All samples of non-fat dry milks which were low in TCA-soluble peptides showed low-acid production, but those high in TCA-soluble peptides showed high-acid production. The addition of trypsin-hydrolysate of Na-caseinate to non-fat dry milk showed some improving effect on acid production but that of papain-hydrolysate did not show any improving effect and that of bacterical neutral protease-hydrolysate showed some inhibitory effect. The improving effects on growth and acid production of lactic acid bacteria were more prominent when the trypsin-hydrolysate of Na-caseinate was added. to such fermenting system in which the levels of TCA-soluble peptides and the proteolytic ability of starter bacteria were abnormally low. The liquid-yoghurt made with non-hydrolysed Na-caseinate and defective non-fat dry milk showed precipitate occurrence but that with trypsin-hydrolysate of Na-caseinate and defective non-fat dry milk did not make any precipitate during storage as with normal non-fat dry milk.