• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.238-242
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• 2008

In this study, hydrogen sulfide ($H_2S$) production was examined during beer fermentation using two ale and two lager yeast strains. In the lager yeast fermentation, a large amount of $H_2S$ was produced in the early fermentation stages when the yeast were actively fermenting wort, indicating a positive relationship between the level of H2S production and the yeast growth rate during fermentation. The ale yeasts produced much lower levels of H2S than the lager yeasts. In the lager fermentation, a higher fermentation temperature shortened the fermentation period, but much higher levels of $H_2S$ were produced at higher temperatures. American pilsner lager yeast fermenting at $15^{\circ}C$ produced a relatively high level of $H_2S$ at the end of fermentation, which would require a longer aging time to remove this malodorous volatile sulfur compound. Not including the English ale strain, which produced a higher level of H2S at lower temperatures, the ale yeast produced lower levels of $H_2S$ at lower temperatures, suggesting that each strain has an optimum fermentation temperature for H2S production.

• Journal of Chest Surgery
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• v.37 no.3
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• pp.292-296
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• 2004

Cryptococcus neoformans is a ubiquitous fungus found worldwide, particularly in soil contaminated by pigeon drop- pings. Pulmonary cryptococcosis occurs rarely in immunocompetent individuals. The risk of cryptococcal infection increases with the degree of immunal compromise, in human immunodeficiency virus infection especially. Pulmonary cryptococcosis is most frequently encountered as asymptomatic single or multiple pulmonary nodules found by routine chest x-ray examination. The diagnosis is most often made in these situations by the histology of the resected lesion. Acute progressive pneumonia may occur, with symptoms of cough, sputum production, fever, and weakness. The clinical picture is not pathognomonic. The yeasts are stained well by any of the special stains for fungi. Treatment is now indicated for all cases given a diagnosis of cryptococcosis, even if the diagnosis has been made by resecton of a solitary, asymptomatic pulmonary nodule.

• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.568-574
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• 1991

The cloned glyceraldehyde-3-phosphate dehydrogenase (GAP) gene of Saccharomyces cereviszae (Holland et al., 1983) has been characterized. Based on the communication, we have also cloned 2.1 kb CAP DNA fragment and modified this fragment as a portable promoter. Two yeast expression vectors, one is YCp type vector being maintained at low copy number (1 or 2) and the other is YEp type vector at high copy number, have been constructed with the GAP promoter and the PH05' gene as a reporter. Our plasrnids were introduc,ed into S. cerevisiae HY-1, which has been improved. The $Trp^+$ transformants expressed APase activity efficiently and showed high level of PH05' transcripts.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.293-297
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• 2002

The cyclodextrin glucanotransferase (CGTase) gene from Bacillus stearothermophilus NO2 was expressed in Saccharomyces cerevisiae 2805 under the adhl promoter. The CGTase was purified from S. cerevisiae 2805/pVT-CGTS. The purified enzyme exhibited a optima of activity around pH 7.0 and $65^{\circ}C$. Thermal stability of the enzyme was increased fairly as compared with the CGTase of B. stearothermophilus NO2. The conversion yield of cyclodextrin (CD) and the production ratio of $\alpha$-, $\beta$,-, ${\gamma}$-CD from starch were showed similarly aspect to the CGTase of B. stearothermophilus NO2.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.3
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• pp.357-363
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• 2000

고추장의 품질을 향상시키고 재래식 전통 고추장과 유사한 맛을 지닌 고추장을 만들기 위해 재래식 전통 고추장에서 분리한 B.licheniformis 균주와 공장에서 대량 생산을 위해 개량해온 A. oryzae와, 비교적 호염성이며 알콜 발효 능력이 우수한 S.rouxii를 혼용하여 고추장을 담근 후 180일까지의 각 고추장의 이화학적 특성 변화를 조사한 결과는 다음과 같다. 단도는 모든 구에서 숙성 30일 까지 급격히 증가한 후 180일까지 거의 일정한 수준을 유지하였으며, 곰팡이 단용구에 비해 고초균과 효모 혼용구에서 숙성 기간 동안 높은 적정산도 값을 보였다. 조단백질은 숙성 기간 동안 대조구에서는 숙성 60일까지 약간 증가한 후 숙성 120일까지 급격히 감소하였으며 고초균 혼용구와 효모 첨가구는 숙성 90일 이후 감소한 후 숙성 120일 이후부터는 거의 변화가 없었다. 숙성 90일 이후부터는 B. licheniformis와 효모 혼용구에서 A. oryzae 단용구보다 조단백질 함량이 높았다. 환원당은 세 구간 모두 숙성 60일 경까지는 증가하는 추세를 보였으며, A. oryzae 단용구보다 B.licheniformis 균주와의 혼용구에서 높은 수치를 보여주었다. 비휘발성 유기산은 숙성 기간이 경과하면서 증가하였고 가장 많이 검출된 유기산은 pyroglutamic acid와 citric acid의 순이었다. 따라서 고추장의 숙성 과정 중 이화학적 특성 변화의 측면에서 볼 때 고초균과 효모 혼용구로 제조된 고추장이 구수한 맛의 생성면에서 유용한 담금법인 것으로 사료된다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.5
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• pp.375-380
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• 1990

It was attempted in this experiment to observe the effect of ginseng saponin on the growth and recovery rate of Saccharomyces rouxii which was shocked by heat-stress. The growth of S. rouxii was found most active when the saponin concentration in the malt extract broth was $10^{-3}%$ And the growth rate of S. rouxii grown on medium containing $10^{-3}%$ ginseng saponin was faster thanh that of the yeast grown on medium without saponin from the early log phase of the yeast. The growth recovery rate of S. rouxii which was heat-shockied by $80^{\circ}C$ - 30 minites was accelerated in the medium added ginseng saponin.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.49-55
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• 2001

For the production of probiotic feed enriched with viable yeasts, aerobic liquid culture of Kluyveromyces marxianus was attempted in pulverized residual food wastes. After the preliminary shaking culture result, the liquid food wastes was added with urea($0.5g/{\ell}$), o-phosphate($0.4g/{\ell}$ ), molasses($4g/{\ell}$), and yeast extract($1g/{\ell}$), and the fermentation was carried out in 2-litre jar fermenter. In 12 hours of aerobic mixed culture with Aspersillus oryzae, viable cell count of the yeast reached to the number of $1.4{\times}10^{10}/{\ell}$ in the cultured medium.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.199.1-199
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• 2003

제주민속주인 좁쌀약주의 제조를 위하여 전국에서 수집된 35종의 누룩으로부터 우수 곰팡이와 효모를 분리하였다. 수집된 누룩의 균수는 곰팡이가 6.4$\times$105~107개, 효모는 1.4$\times$104~107개로 나타났고, 이 중에서 곰팡이 169균주, 효모 103균주를 분리하였으며 전분당화력이 좋은 곰팡이 16균주와 효모 1균주를 선발하였다. 이 중에서 전분당화 균주의 효소활성을 분석한 결과 Aspergillus속으로 동정된 A8-3이 glucoamylase 활성, 액화력, xylanase 활성이 가장 높았고, Rhizopus속으로 동정된 B23-3은 당화력이 가장 우수하였다. 우수효모를 선발하기 위하여 pH, 무게 감량, 내당성, 내알코올성 등을 측정한 결과, Saccharomyces속인 A10-4가 가장 우수하였다. 같은 원료비율로 만든 누룩에 우수균주를 접종하였을 때, 단일 균주를 처리할 때보다 A8-3과 B23-3인 두 균주를 혼합하여 처리한 경우가 당화력이 높게 나타났다. 누룩을 원반형의 누룩과 팰릿(개량형) 형태로 만들어 혼합종균 배양액을 접종한 후 당화력을 측정한 결과, 비슷한 당화력을 나타내었다. 개량형 누룩을 사용하여 양조하는 경우, 좁쌀주 양조에 발효효율을 높일 수 있을 것으로 판단되었다. 수집된 누룩은 수분이 10~13%, 총당은 55~70%, 조단백질은 10~18% 조지방은 0.2~l.0%, 회분은 1.8~2.1%이었다. 본 연구에서 제조한 누룩은 수분이 12~15%, 총당은 61~7l%, 조단백질은 15~20%, 조지방은 0.4~1.5%, 회분은 1.1~1.5%이었다.

• Food Science and Preservation
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• v.10 no.3
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• pp.417-420
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• 2003

In order to study optimum culture condition of yeast medium added deep seawater, we examed samples with 9 yeast strains. The growth rate were measured for Saccharomyces cerevisiae 10, 11, 12, 901 and RCY and Saccharomyces kluyvery DJ97, Saccharomyces cerevisiae YJK, JK99, CMY-28 etc.. The growth of S. cerevisiae 12 was found most active in the deep seawater(hardness 500). The growth rate of S. cerevisiae 901 on medium containing deep seawater(hardness 1000) was faster than that of the yeast on medium without deep seawater. The use of deep seawater on the growth of Sacch.cerevisiae kluyvery DJ97 revealed maximum growth under the condition of hardness 200 of deep seawater and 10％ of sugar concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.321-326
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• 2016

The objective of this study was to obtain data on safety-in-use of yeast hydrolysate with a molecular weight of 10~30 kDa as a dietary supplement by assessing its subacute oral toxicity in ovariectomized rats. Yeast hydrolysate did not produce mortality or significant changes in general behavior or gross appearance of internal organs of rats. There were no significant differences in organ weights between control and yeast hydrolysate groups. Hematological analysis and blood chemistry revealed no toxic effects of yeast hydrolysate. Neither gross abnormalities nor histopathological changes were observed. These results show that yeast hydrolysate possesses very low toxicity as indicated in a postmenopausal animal model.