• KSBB Journal
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• 제13권3호
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• pp.308-311
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• 1998

A novel process was developed to simultaneously produce invertase and yeast extract from baker's yeast using ultrafiltration (UF) and microfiltration (MF) membrane processing. After the extraction of invertase under the optimal condition obtained in this study, invertase was separated from yeast cells using a hollow fiber membrane with a pore size of 0.1 $\mu\textrm{m}$. The resulting permeate containing invertase was concentrated using a hollow fiber membrane with a nominal molecular weight cut-off of 30 kDa. The yeast cell and permeate solutions, which were obtained after MF and UF membrane processing, respectively, were mixed together, and the autolysis was performed at 50$^{\circ}C$ in the presence of 5% (w/v) ethanol and 1% (w/v) NaCl. As a result, the yeast extract and invertase could be simultaneously produced from baker's yeast by this novel process.

• 한국식품영양학회지
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• 제8권4호
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• pp.280-288
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• 1995

Because yeast is rich in vitamins, nucleotides and essential amino acids, it has been used as a nutrient and dietary supplements. Particularly yeast extract functions as a seasoning, flavor enhancer in meats. In this study, naturally occurring insoluble components during yeast extract process by autolysis were microanalyses by using SEM, XRD, HPLC, GC, FT-lR and DSC. On the basis of useful datas, authors have characterized the analytical points for the purpose of improving products in the preparation of yeast extract.

• 생명과학회지
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• 제18권4호
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• pp.550-555
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• 2008

홍삼액의 첨가에 따른 발효가능성을 알아보기 위하여 홍삼액의 첨가량을 달리하여 발효특성을 조사하였다. 본 실험에서는 Saccharomyces cerevisiae JF-Y3을 이용하여 발효를 실시하였으며, 홍삼액($20\;^{\circ}brix$) 함량 $10{\sim}50%$, yeast extract $0.5{\sim}2.5%$의 범위로 중심합성계획법에 의하여 10개의 구간으로 홍삼액의 알코올 발효특성을 살펴보았다. 효모수는 홍삼액 및 yeast extract 농도 모두에 영향을 받고 있었으며, 홍삼액 농도에 더 많은 영향을 받는 것으로 나타났다. 홍삼액 농도가 감소하고, yeast extract 농도가 증가할수록 효모수가 증가하는 것으로 나타났다. 알코올 함량이 가장 높게 나타난 발효조건은 홍삼액 함량 30%, yeast extract 함량 0.50%이었으며, 이때의 최대값은 12.45%로 예측되었다. 당도 및 총당 함량의 경우 각각 1%이내의 유의수준에서 유의성이 인정되었고, 당도의 경우 홍삼액 및 yeast extract 함량 두 조건에 모두 영향을 받는 것으로 나타났으며, 총당 함량의 경우 주로 홍삼액 농도에 영향을 받는 것으로 나타났다. 홍삼액 $20\;^{\circ}brix$의 함량을 $10{\sim}50%$까지 증가하여도 발효액의 알코올 함량이 모두 10% 이상이었으며, 전반적으로 홍삼액 첨가에 따른 발효의 저해는 크게 일어나지 않는 것으로 나타나 홍삼의 유효한 성분을 이용한 기능성 주류 개발 시 홍삼농축액을 효율적으로 활용할 수 있을 것이다. 또한, 앞으로 홍삼액 발효 시의 알코올 성분에 대한 분석, 발효액에 대한 관능적 특성, 유효성분 등에 대한 특성 변화 등을 통한 고품질 홍삼주 제조와 관련하여 추가적인 연구가 필요할 것으로 생각된다.

• Mycobiology
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• 제39권2호
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• pp.85-91
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• 2011

We investigated the effect of nutritional and environmental factors on Ophiocordyceps longissima mycelial growth. The longest colony diameter was observed on Schizophyllum (mushroom) genetics complete medium plus yeast extract, Schizophyllum (mushroom) genetics minimal medium, and Sabouraud dextrose agar (SDA); however, malt-extract yeast-extract agar, SDA plus yeast extract, yeast-extract malt-extract peptone dextrose agar, SDA, oatmeal agar, and potato dextrose agar showed higher mycelia density. A temperature of $25^{\circ}C$ was optimum and 7.0 was the optimum pH for mycelial growth. Colony diameter was similar under light and dark conditions. Maltose and yeast extract showed the highest mycelial growth among carbon and nitrogen sources respectively. The effect of mineral salts was less obvious; however, $K_3PO_4$ showed slightly better growth than that of the other mineral salts tested. Among all nutrition sources tested, complex organic nitrogen sources such as yeast extract, peptone, and tryptone were best for mycelial growth of O. longissima. Ophiocordyceps longissima composite medium, formulated by adding maltose (2% w/v), yeast extract (1% w/v), and $K_3PO_4$ (0.05% w/v) resulted in slightly longer colony diameter. In vitro mycelial O. longissima growth was sustainable and the production of fruiting bodies could be used for commercial purposes in the future.

• Biotechnology and Bioprocess Engineering:BBE
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• 제4권1호
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• pp.21-25
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• 1999

Two low-salt complex media, bactopeptone and desalted yeast extract, were used for high density cultivation of the hyperthermophilic archaeon Sulfolobus solfataricus (DSM 1617). Bactopeptone, which has low mineral ion content among various complex media, was good for cell growth in batch cultures; the maximal cell density in bactopeptone was comparable to that in yeast extract. However, cell growth was rather poor when bactopeptone was added by the fed-batch procedure. Since several vitamins are deficient in abctopeptone, the effect of vitamins on cell growth was examined. Among the vitamins tested, pyridoxine was found to improve the growth rate of S. solfataricus. To reduce the growth inhibition caused by mineral ions, yeast extract was dialyzed against distilled water and then fed-batch cultures were carried out using a fed medium containing desalted yeast extract. Although the concentrations of mineral ions in yeast extract were significantly lowered by the dialysis whether low molecular weight solutes in yest extract are crucial for cell growth, we investigated the effect of trehalose, a most abundant compatible solute in yeast extract, on the growth pattern. Cell densities were increased and the length of the lag phase was markedly shortened by the presence of trehalose, indicating that trehalose plays an important role in the growth of S. solfataricus.

• 한국균학회지
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• 제26권3호통권86호
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• pp.361-364
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• 1998

시험한 유기 질소원 중 yeast extract와 soytone이 Tricholoma matsutake DGUM 26001의 균사생장에 가장 우수한 질소원이었다. Yeast extract를 starch-pyridoxine 배지에 1.0% 농도까지 첨가하였을 때, 균사생장이 증가하였다. $24^{\circ}C$에서 30일간 yeast extract가 첨가된 배지에서 배양하였을 때, 50 ml 배양액에서 518 mg의 건조 균사체를 얻을 수 있었다.

• Journal of Dairy Science and Biotechnology
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• 제37권1호
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• pp.57-68
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• 2019

The effects of yogurt supplementation with enzyme-bioconverted ginseng (EBG), ascorbic acid, and yeast extract on the bacterial counts of Streptococcus thermophilus, Lactobacillus acidophilus LA-5, and Bifidobacterium BB-12 were investigated to develop healthy yogurts with high probiotic counts during storage. In addition, the colors and viscosities of the yogurts were determined. EBG, ascorbic acid, and yeast extract did not affect S. thermophilus counts. EBG and ascorbic acid enhanced the viabilities of L. acidophilus LA-5 and Bifidobacterium BB-12 during storage. Yeast extract improved growth of L. acidophilus LA-5 and Bifidobacterium BB-12 during fermentation. EBG turned the yogurt into brown color. We conclude that supplementation of yogurt with EBG, ascorbic acid, and yeast extract may enhance its health-promoting functions by increasing the viability of probiotics, which can thus promote consumption of the yogurt.

• Journal of Ginseng Research
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• 제10권1호
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• pp.1-10
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• 1986

인삼의 부산물중에서 박의 활용가능성을 조사하기 위하여 박의 구성성분, ext의 DPPH 환원력, 효모생육에 미치는 영향 및 효모균체내의 amino acid함량등에 미치는 영향등을 조사한 결과를 요약하면 다음과 같다. 박내에는 총당이 43~46%, 조단백이 14~15%, n-BuOH ext함량은 0.18% 였으며 alcohol박의 물ext는 alcohol ext에 비해 약 46%정도의 DPPH환원력이 남아있었으며 박ext를 첨가하고 효모를 배양시켰을 때 효모의 생육에 필요한 영양물질이나 생육을 촉진하는 물질이 박ext내에 존재하고 있다는 것을 알았으며 알콜박의 물추출물을 첨가하여 배양한 효모균체의 amino acid함량이 다른 ext를 첨가한 효모균체보다 많았다. 박에 cellulase를 0.1%, 20분간 처리로 박ext의 수율을 250%정도 증가시킬 수 있었다.

• Applied Biological Chemistry
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• 제50권1호
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• pp.6-11
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• 2007

P. freudenreichii KCCM 31227을 whey 배지에서 배양시 whey 배지의 살균방법 즉, 고압증기멸균(121$^{\circ}C$, 15분), 저온살균(60$^{\circ}C$, 30분) 방법과 배양액에 yeast extract를 0.5, 1% 첨가하였을 때 생균수와 총산도를 측정하여 P. freudenreichii KCCM 31227의 생육특성을 조사하였다. 6% whey 배지보다는 12% whey 배지에서, yeast extract 0.5% 보다는 1.0% 첨가 시 생균수가 높았고, 12% whey 배지에 yeast extract를 1.0% 첨가하고 저온살균하였을 때 배양 72시간에 7.5${\times}10^7$ cfu/ml로 가장 높은 생균수를 나타냈다. 총산도는 12% whey 배지에 yeast extract를 1.0% 첨가하여 저온살균하였을 때 5.2로 가장 높았다. 배양 72시간 동안 생균수와 총산도의 증가는 유사한 경향을 보여주었다. Propionic acid와 acetic acid의 생성은 고온살균보다 저온살균에서 높게 검출되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제1권1호
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• pp.41-45
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• 1996

Effects of yeast extract and ammonium sulfate were investigated on the production of L-or-nithine by an arginine auxotroph, Brevibacterium ketoglutamicum in flask and batch cultures. Yeast extract as an arginine source and ammonium sulfate as an inorganic nitrogen source had significant effects on L-ornithine production and cell growth. L-ornithine production was repressed by the excessive addition of arginine. Reversion of auxotrophic cells to the wild type was observed when the initial yeast extract concenfration was too low. There existed optimum concentrations of yeast extract and ammonium sulfate for L-or-nithine production. The effects of yeast extract and ammonium sulfate concentrations of the Leudeking-Piret model parameters were examined to analyze the relationship between cell growth and L-ornithine production.