• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.221-225
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• 1992

The possibility of using Chinese cabbage juice as a substrate for the production of Candida utilis cell mass was explored. Dry cell weight production and cell yield coefficient were 1.35-1.45 g/100 ml undiluted juice and 47-50%, respectively, when C. utilis was grown by shake flask culture at $30^{\circ}C$ for 24 hr on more than three-fold diluted Chinese cabbage juice to make the final sugar content be equal to or less than 1.0%. Supplementation of glucose(2%), $KH_2PO_4(0.2%)$ and $(NH_4)_2SO_4(0.2%)$ to three-fold diluted Chinese cabbage juice did not enhance the dry cell weight yield or the protein content of the yeast cell, while supplementation of yeast extract(0.2%) and peptone(0.2%) increased dry cell weight production and protein content but not as much as the amount of each nutrient added. It was found that Chinese cabbage juice was an excellent substrate for the cultivation of C. utilis.

• Microbiology and Biotechnology Letters
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• v.16 no.2
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• pp.105-110
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• 1988

The production of single cell protein using the amylolytic fusant obtained from cell fusion between Hansenula anomala and Saccharomyces cerevisiae was studied. The fusant12 strain was selected for single cell protein production from starchy materials among five fusants. Optimum nitrogen source and its concentration for the growth of fusant12 were ammonium sulfate and 0.1%, respectively. Optimum concentration of soluble starch and optimum pH of the basal medium were lord and pH 5.6, respectively. Autolysis of fusant12 was effectively carried out by addition of 5% (v/v) ethyl acetate to the cell suspension and liquidization for 30 min before incubation for 24 hr at 3$0^{\circ}C$. Coculture of fusant12 and non-amylolytic yeast, Torulopsis candida YA-l5, resulted in the increase of the mass as compared to the monoculture of fusant12. The cell mass on tapioca medium was increased about 2.5 times as on soluble starch medium. The content of crude protein and nucleic acid of the dry cell were 39% and 5.8%, respectively.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.224-227
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• 2022

In this study, the protective effects of turanose on Saccharomyces cerevisiae (Baker's yeast) were examined during the freeze-drying process to evaluate the feasibility of utilizing turanose as a novel cryoprotectant. The survival rate of the Baker's yeast cells improved substantially with a cryoprotective medium containing turanose in a substitution-dependent manner. In accordance with these survival rates, the yeast cell surfaces became smoother as the turanose content increased. Turanose with skim milk maintained the viability of the Baker's yeast, which improved substantially upon storage at -20℃. Thus, it is thought that turanose will exhibit excellent preservation effects during the distribution of Baker's yeast. Finally, these results suggest that turanose has the potential to be used as a novel cryoprotectant against various microorganisms.

• Journal of the Korean Chemical Society
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• v.47 no.4
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• pp.363-369
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• 2003

Selenized yeast (Se yeast) containing $0.1{\%}$(w/w) of selenium was obtained when the yeast was incubated at a selenium concentration of 1$1.14{\times}10_-3 M$ in rich medium. After washing several times, the inorganic selenium on the cell wall was confirmed with MBRT. There was no indication of inorganic selenium on the cell wall when the blue color in MBRT was stayed for 15 minutes. The selenized yeast was sonicated, then the selenium contained protein was obtained after salting out by ammonium sulfate at the concentration $80{\%}$ saturation. The seven protein bands were seperated by SDS-PAGE and the selenium concentration in protein was measured by ICP-AES. Analytical data showed that the large expressed protein band contained a relatively large amount of selenium. The proteins of the 47kDa was contained the concentrations of 69.5 ${\mu}$ Se/g of most many content. The protein (47 kDa) was seperated from PVDF membrane by tank-electroblotting. The isolated protein was hydrolyzed under acid condition and reacted with PITC. The derivatives of amino acids were analyzed by HPLC and compared with the data obtained from regular yeast. The resulting selenium-yeast was analyzed with the selenomethionine concentration of $2{\%}$ comparaed with general amino acids. The goal of this study is to analyze the selenium concentration in protein bands and measure the degree of biotransformation of selenomethionine in a specific protein.

• Journal of Aquaculture
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• v.9 no.4
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• pp.329-337
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• 1996

Dietary values of phytoplanktons, concentrated Chlorella and commercial yeasts were investigated for the resting egg production of the Korean rotifer, B. plioatilis S-type. The hatching rate of the resting egg of the rotifer fed on different diets was also studied. The highest production of the resting egg was 3,760 eggs/20 ml with N. oculata. However, the hatching rate was not significant among 4 phytoplankton species. The highest production of resting eggs among 9 diet groups ($\omega$-yeast, baker's yeast, 2 refrigerated Marine Chlorella, frozen Marine Chlorella, frozen Chlorella ($70\%$) + baker's yeast ($30\%$), frozen Chlorella ($30\%$) + baker's yeast ($70\%$), 2 refrigerated freshwater Chiorella) was 283 eggs/ml in the frozen Chlorella ($30\%$) +baker's yeast ($70\%$) and the refrigerated freshwater Chlorella. The highest number of resting egg from 10,000 rotifers and 1 mg dry wieght diet was 5,566 eggs and 2,131 eggs in the frozen Chlorella ($30\%$) + baker's yeast ($70\%$). However, the highest hatching rate of the resting eggs was $67.4\%$ in $\omega$-yeast. In this study, the results suggest that the baker's yeast with a small amount of frozen Chlorella seems to be good feeding regime for the economical production of resting eggs.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.258-263
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• 1987

The waste gained from alcohol production with sweet potato was considered as a potential substrate for the production of single cell protein (SCP). The high content in organic materials, simplicity to filtrate and a suitable pH for the growth of yeasts were indicated as a good substrate. A yeast utilizing this substrate was isolated from the compost ground and identified as Candida boidinii. The strain was the highest in assimilation of this alcoholic waste and the yield was maximized at pH 5.0, $30^{\circ}C$ after 72 hrs incubation. The dry cell weight and crude protein content at optimal conditions were 1.02g/100ml and 54.5%, respectively. The growth of the yeast was stimulated with the addition of 0.2% urea, 0.1% $K_2HPO_4$, and 0.02% $MgSO_4{\cdot}7H_2O$.

• KSBB Journal
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• v.9 no.1
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• pp.8-15
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• 1994

The research has been carried out to optimize a recombinant S. cerevisine fermentation process for the production of an anticoagulant hirudin. The structural gene coding for hirudin was combined with the GAL10 promoter for controlled expression, the MFal signal sequence for hirudin secretion, and the GAL7 terminator for transcriptional termination. Growth medium composition and environmental conditions were optimized for maximizing cell growth and final hirudin concentration. The optimized conditions included yeast extract 40g/$\ell$, casamino acid 5g/$\ell$, g1ucose 20g/$\ell$, galactose 30g/$\ell$, DO 50% and temperature $30^{\circ}C$. These conditions yielded the specific cell growth rate of $0.13hr^{-1}$, the final cell density of 30g cell/$\ell$ and the final hirudin concentration of 64mg/$\ell$ in the batch fermentation with a 2.5$\ell$ jar fermentor.

• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.242-248
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• 1979

To detect proper lytic assay conditions of the crude zumolyase from Arthrobacter luteus, effets of the various factors involved in the lytic system of Sacchromyces sake cultured with shaking in the malt extracts medium were investigated. The results are summarized as follows : 1. The susceptibilities of viable cells of S. sake from logarithmic growth phase to the lytic enzmye were much greater than those of the cells in lag and stationary phases. The cells cultured for 18 hr were the most susceptible to the enzyme. 2. Lytic activity of the enzyme toward the viable cells of S. sake was very low. It was, however, enhanced 4 folds of more by the pretreatment of the cells with 0.05 M sodium sulfite. 3. Lytic activity of the enzyme toward commercial baker's yeast cells was negligible, and the effect of sodium sulfite on the lysis of the cells also was nothing but a little. 4. The lyophilized cells of the baker's yeast showed more susceptibility to the lytic enzyme than viable cells of the yeast. No definite effect of sodium sulfite on the lysis of the lyophilized cells, however, was observed either baker's yeast of S. sake. 5. It appeared that the relationship between the reaction rate and the enzyme concentration on the lysis of the yeast cell walls followed enzyme kinetic theory, but one between the reaction rate and concentration of the yeast cells as substrates showed different pattern from that in enzyme kinetic theory. 6. After the preparation of crude zymolyase was kept at $7^[\circ}C$ for 10 days in the 0.05 M phosphate buffer, pH 7.5, the remainning lytic activity was about 80 %.

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.302-308
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• 2005

To examine the difference in each ingredient between the yeast strain and two raspberry kinds (Rubus crataegifolius Bunge(RCB), Rubus coreanus Miquel(RCM)) in the making of raspberry wine, five active dry yeasts were selected. Regarding the RCM ethanol content, the raspberry wine fermented by Lalvin Wl5 was the highest, while those fermented by Prise de Mousse were the lowest. The pH of the RCM was $3.58\~3.63$, and Montrachet was the highest one of total acidity. In the case of nonflavonoid phenols, the RCM fermented by Montrachet was the highest one, and in the case of flavonoid phenol and total phenol, the RCM fermented by Epernay II was the highest. The content of organic acid in RCM were highest in the following order: citric acid > oxalic acid > malic acid, and tartaric acid was not detected at all. The average content of malic acid in RCM after malolactic fermentation was reduced by almost $65.5\%$, and the RCM fermented by Prise de Mousse, after malolactic fermentation, was $73.3\%$. This latter was the highest, while the RCM fermented by Epernay II was the lowest, at $59.1\%$.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.646-648
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• 1991

A possibility of utilizing Chinese cabbage, a kind of renewable resources which is frequently overproduced in Korea, for the production of single cell protein was investigated. Saccharomyces cerevisiae and Candida utilis grew well in cabbage juice producing 4.3 and 5.1 g/l of dried yeast cells, respectively. Freezing fresh cabbage prior to juice extraction did not affect the growth of yeasts and the final cell yield.