• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1673-1680
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• 2012

In this study, DEAE-corncobs [delignified corncob grits derivatized with 2-(diethylamino)ethyl chloride hydrochloride ($DEAE{\cdot}HCl$)] were prepared as a carrier to immobilize yeast (Saccharomyces cerevisiae) for ethanol production. The immobilized yeast cell reactor produced ethanol under optimized $DEAE{\cdot}HCl$ derivatization and adsorption conditions between yeast cells and the DEAE-corncobs. When delignified corncob grit (3.0 g) was derivatized with 0.5M $DEAE{\cdot}HCl$, the yeast cell suspension ($OD_{600}$ = 3.0) was adsorbed at >90% of the initial cell $OD_{600}$. This amount of adsorbed yeast cells was estimated to be 5.36 mg-dry cells/g-DEAE corncobs. The $Q_{max}$ (the maximum cell adsorption by the carrier) of the DEAE-corncobs was estimated to be 25.1 (mg/g), based on a Languir model biosorption isotherm experiment. When we conducted a batch culture with medium recycling using the immobilized yeast cells, the yeast cells on DEAE-corncobs produced ethanol gradually, according to glucose consumption, without cells detaching from the DEAE-corncobs. We observed under electron microscopy that the yeast cells grew on the surface and in the holes of the DEAE-corncobs. In a future study, DEAE-corncobs and the immobilized yeast cell reactor system will contribute to bioethanol production from biomass hydrolysates.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.347-350
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• 2001

The dextran prodution by Leuconostoc mensenteroids NRRL-B512F was studied in a synthetic medium from sucrose as a sole carbon source. Especially, effect of nitrogen source was treated and compared in this study. In oder to maximize the cell growth and dextran produtivity through fermentation two nitrogen sources, yeast extract and tryptone, were used with various concentrations. At the end of fermentation, when the concentration of yeast extract was 9g/L we can obtain the maximum dry cell weight(14.1g/L), dextran dry weight(25.4g/L) and productivity(1.4g/L ${\cdot}$ hr).

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.830-835
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• 2004

An experiment of 10 weeks duration was carried out to study the influence of supplemental effective microorganism (EM) culture, yeast culture and enzymes on nutrient digestibility and gut microflora in rabbit gastrointestinal (GI) tract. Twenty four eight to nine weeks old, New Zealand White rabbits were allotted to four dietary treatments; a basal (control) feed, basal feed supplemented with either EM (1%), yeast culture or enzymes (400 ppm). Nutrient flow in digesta and their digestibility at ileum, caecum, colon and in the total tract as well as gut microflora distribution were studied. Feed dry matter was diluted from 92% to about 14% up to the ileum and about 95% of this water was reabsorbed by the colonic rectal segment followed by caecum (25%). EM and yeast improved protein digestibility at a lower rate than enzymes. Ileal, caecal, colonic and total tract digestibility of crude protein with enzymes were higher by 10.8, 9.4, 11.3 and 10.7%, respectively, as compared to the control. Yeast and enzymes increased crude fiber digestibility at ileum, caecum, colon and in the total tract by 8.5, 9.6, 9.0 and 8.3%, respectively, while EM improved them at a lower rate. Irrespective of treatments, total tract digestibility of crude protein (0.698-0.773) and fiber (0.169-0.183) were greater (p<0.05) than the ileal digestibility. Even though a post-caecal protein digestibility was observed, fiber digestion seemed to be completed in the caecum especially with yeast and enzymes. High precaecal digestibility of crude fiber (97%) and protein (95%) were observed even without additives probably due to caecotrophy. EM and yeast culture promoted the growth of lactic acid bacteria especially in the caecum but they did not influence gut yeast and mould. Present findings reveal that even though rabbits digest nutrients efficiently through hind gut fermentation, they can be further enhanced by EM, yeast and enzymes. Of the three additives tested, enzymes found to be the best.

• Mycobiology
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• v.42 no.4
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• pp.361-367
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• 2014

Makgeolli, also known as Takju, is a non-filtered traditional Korean alcoholic beverage that contains various floating matter, including yeast cells, which contributes to its high physiological functionality. In the present study, we assessed the levels of ${\beta}$-glucan and glutathione in various yeast strains isolated from traditional Korean Nuruk and selected a ${\beta}$-glucan- and glutathione-rich yeast strain to add value to Makgeolli by enhancing its physiological functionality through increased levels of these compounds. Yeast ${\beta}$-glucan levels ranged from 6.26% to 32.69% (dry basis) and were strongly species-dependent. Dried Saccharomyces cerevisiae isolated from Nuruk contained $25.53{\mu}g/mg$ glutathione, $0.70{\mu}g/mg$ oxidized glutathione, and $11.69{\mu}g/g$ and $47.85{\mu}g/g$ spermidine and L-ornithine monohydrochloride, respectively. To produce functional Makgeolli, a ${\beta}$-glucan- and glutathione-rich yeast strain was selected in a screening analysis. Makgeolli fermented with the selected yeast strain contained higher ${\beta}$-glucan and glutathione levels than commercial Makgeolli. Using the selected yeast strain to produce Makgeolli with high ${\beta}$-glucan and glutathione content may enable the production of functional Makgeolli.

• Textile Coloration and Finishing
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• v.33 no.4
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• pp.191-201
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• 2021

In this study, an eco-friendly indigo reduction system(scale up reduction, use of buffer solution, and pH control) using baker's yeast(Saccharomyces cerevisiae) was applied for natural indigo(Polygonum tinctorium) dyeing of Hanji fabric and Hanji-mixture fabric(Hanji/Cotton, Hanji/Silk). The effect of concentration of baker's yeast, repeat dyeing, and bath reuse was investigated in terms of dye uptake indicating reduction power. And the oxidation-reduction potential(ORP) was monitored. We also evaluated color properties and colorfastness according to the color strength. The yeast concentration did not significantly affect the maximum reduction power. However, the highest yeast concentration was effective in improving the initial dye uptake, and its the reduction retention power was the most excellent. Even on the last reduction day, the effect of increasing the dye uptake by repeat dyeing was observed. And it was confirmed that the reduction bath could be reused for up to 30 days by supplementing yeast at the end of reduction. For all the fabrics used, deeper and darker PB color were obtained by repeat dyeing. As dyeing was repeated, purplish tint got stronger on the Hanji/Silk fabric compared to other fabrics. Regardless of the composition of Hanji fabrics and color strength, washing and dry cleaning fastness were relatively good with above rating 4-5, and fastness to rubbing and light were acceptable with a rating 3-4 ~ 4-5. The eco-friendly natural indigo dyeing process using niram and baker's yeast would offer global marketability and diversity of Hanji product as a sustainable high value-added material.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.32-39
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• 2015

Objective of this study was to investigate characteristics of inorganic components contained in liquid fertilizer produced using seaweed by adding microorganisms and molasses. Addition of dry yeast to liquid fertilizer resulted in little change in pH and considerable increase in EC with high EC value compared to other liquid fertilizers which have microorganisms additives. Also, it was appeared that the dry yeast-added treatment had higher $NH_4-N$ concentration than other treatments. In the other hand, addition of molasses resulted in low pH compared to the control which has no additives, and EC was not different depending on the amount of molasses. $NH_4-N$ concentration in the 2% molasses added treatment was lowest and it showed a significant difference in the no and 1% molasses added treatments. In conclusion, it was shown that addition of dry yeast to liquid fertilizer increased ammonium nitrogen concentration by accelerating nitrogen mineralization, while molasses has an effect of inhibiting nitrogen mineralization. With application of organic liquid fertilizer containing seaweed increased the fresh weight of chinese cabbage.

• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.95-101
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• 1974

Studies on the optimum conditions of acid hydrolysis of sweet potato starch cake and its utilization on the production of Saccharomyces cerevisiae as a carbon source were conducted and the results showed as follows; 1.The highest hydrolysis rate, 62.7 ％ of the reducing sugar based on the weight of the dry matter, was obtained when the starch cake was hydrolyzed with 1.0％ of hydrochloric acid at 2.0 kg/$\textrm{cm}^2$ for 30 minutes. 2. But the yeast grew most favorably on the hydrolyzate obtained by treating the starch cake with 0.5％ of hydrochloric acid at 2.0 kg/$\textrm{cm}^2$ for 10 minutes. Reducing sugar content of hydrolyzate was 51.4％. 3. The optimum pH of the culture medium was 7.0, Cell growth reached to the maximum at 36 hours of cultivation time. 4. According to the vitamin requirement tests, Ca-pantothenate was found to be a promoting factor for the growth of the yeast cells. 5. "Gluten acid hydrolyzate" was most effective to the cell growth when added to the medium at the concentration of 0.1％ as a nitrogen source. 6. Sacch. cerevisiae could assimilate the sugars in the hydrolyzate about 89.1％, and the yields of the yeast cells showed 23.2mg/ml of culture medium.

• Journal of agriculture & life science
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• v.43 no.5
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• pp.43-46
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• 2009

The one of problems of plug seedlings production in winter season was a poor growth. This study was carried out to investigate the effects of treatments with yeast fertilizers on the growth of pepper seedlings in winter seasons. The plant height, internode length, and shoot and dry weight of pepper seedlings increased significantly by yeast fertilizers. The results showed that yeast fertilizer treatment could be more effective in soaking than foliar spray and that of dilution could be effective in $1,000{\times}$.

• Food Science and Preservation
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• v.15 no.2
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• pp.306-310
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• 2008

This study investigated the effects of 3 different strains of my yeast (Saccharomyces cerevisiae Montrachet (UCD #522), S. bayanus Pasteur Champagne (UCD #595), and S. cerevisiae Epernay (CEG) and two grape varieties (Tamnara and M.B.A) on the quality of red wines. During fermentation, sugar content decreased and alcohol content increased Addition of my yeast increased fermentation speed for both grape varieties. Sensory quality tests and tests with an electronic tongue showed that red wine made from M.B.A grapes was superior to that made from Tamnara grapes and that red wine made without the addition of my yeast was better than that made by using dry yeast.

• Animal Bioscience
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• v.36 no.9
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• pp.1426-1434
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• 2023

Objective: The objective of this study was to evaluate the effect of Debaryomyces hansenii isolated from dry-aged beef on the tenderness and flavor attributes of low-grade beef during dry aging. Methods: Five D. hansenii strains were isolated from dry-aged beef samples. The rump of low-grade beef was inoculated with individual D. hansenii isolates and subjected to dry aging for 4 weeks at 5℃ and 75% relative humidity. Microbial contamination levels, meat quality attributes, and flavor attributes in the dry-aged beef were measured. Results: Of the five isolates, the shear force of dry-aged beef inoculated with SMFM201812-3 and SMFM201905-5 was lower than that of control samples. Meanwhile, all five isolates increased the total free amino acid, glutamic acid, serine, glycine, alanine, and leucine contents in dry-aged beef. In particular, the total fatty acid, palmitic acid, and oleic acid contents in samples inoculated with D. hansenii SMFM201905-5 were higher than those in control samples. Conclusion: These results indicate that D. hansenii SMFM201905-5 might be used to improve the quality of beef during dry aging.