• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1385-1392
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• 2009

This work evaluates the effect of different amino acids on production of Cyclosporin (CyA) production in solid-state fermentation that was previously optimized for different fermentation parameters by one factor at-a-time for the maximum production of CyA by Tolypocladium inflatum MTCC557. Based on the Plackett-Burman design, glycerol, ammonium sulfate, $FeCl_3$, and inoculum size were selected for further optimization by response surface methodology (RSM). After identifying effective nutrients, RSM was used to develop mathematical model equations, study responses, and establish the optimum concentrations of the key nutrients for higher CyA production. It was observed that supplementation of medium containing (% w/w) glycerol, 1.53; ammonium sulfate, 0.95; $FeCl_3$, 0.18; and inoculum size 6.4 ml/5g yielded a maximum of 7,106 mg/kg as compared with 6,480 mg CyA/kg substrate using one factor at-a-time. In the second step, the effect of amino acids on the production of CyA was studied. Addition of $_L$-valine and $_L$-leucine in combination after 20 h of fermentation resulted in maximum production of 8,166 mg/kg.

• Journal of The Korean Society of Grassland and Forage Science
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• v.32 no.4
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• pp.361-368
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• 2012

The present study was conducted to develop persimmon peel, a by-product of dried persimmon manufacturing, as a feed additive via lactic acid bacteria fermentation. Pediococcus pentosaceus, Lactobacillus plantarum, and three strains of Leuconostoc mesenteroides were used as a starter culture in the solid state fermentation of persimmon peel, and antioxidant activity and total polyphenol content were assessed. Leuconostoc mesenteroides KCTC 3100 showed high antioxidant activity (p<0.05), whereas Pediococcus pentosaceus showed high total polyphenol content (p<0.05). These two strains were thus selected as starter culture strains. Glucose, sucrose and molasses were used as variables for optimization and a total 15 experimental runs were produced according to Box-Behnken design. Regarding significant effects of variables, molasses showed linear and square effects on antioxidant activity of persimmon peel fermentation (p<0.05). In conclusion, optimum concentrations of glucose, sucrose, and molasses were determined to be 4.2, 3.9 and 5.3 g/L, respectively, using a response surface model. Antioxidant activity was also improved 2.5 fold after optimization.

• Journal of the Korean Society of Food Culture
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• v.34 no.2
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• pp.201-207
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• 2019

This review summarizes the studies on a wide variety of yeast found in kimchi and the effects of yeast on kimchi fermentation, and discusses the direction for further research. Yeast belongs to the genera Trichosporon, Saccharomyces, Sporisorium, Pichia, Lodderomyces, Kluyveromyces, Candida, Debaryomyces, Geotrichum, Kazachstania, Brassica, Yarrowia, Hanseniaspora, Brettanomyces, Citeromyces, Rhodotorula, and Torulopsis have been identified using culture-dependent methods and metagenomics analysis. The application of yeast as a starter into kimchi has resulted in an extension of shelf life and improvement of sensory characteristics due to a decrease in the amount of lactic acid. On the other hand, some yeast cause kimchi spoilage, which typically appears as an off-odor, texture-softening, and white-colony or white-film formation on the surface of kimchi. In contrast to lactic acid bacteria, there are limited reports on yeast isolated from kimchi. In addition, it is unclear how yeast affects the fermentation of kimchi and the mechanism by which white colony forming yeast predominate in the later stage of kimchi fermentation. Therefore, more research will be needed to solve these issues.

• Korean journal of food and cookery science
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• v.23 no.2 s.98
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• pp.173-179
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• 2007

The effects of fermentation agent and fermentation temperature on the quality of Bori-sangoedduk We examined the effects of fermentation agent and fermentation temperature on the quality characteristics of Bori-sangoedduk a traditional dduk(rice cake) from Jeju, Korea. Bori-sangoedduk was prepared by mixing wheat flour, barely flour, and Borisul or Takju as the fermentation agent the mixture was then fermented at 30, 35, and $40^{\circ}$C. for 3 hr, and steamed. The L- value of the Takju group was higher than that of the Borisul group, and the samples fermented at $30^{\circ}$C in each group had higher than L-values than those fermented at $35^{\circ}$C and $40^{\circ}$C . The a- and b-values did not differ significantly by the fermentation agents and fermentation temperatures. The loaf volume of the Borisul group was higher than that of the Takju group however, there were no significant differences according to fermentation temperature. The values of hardness, springiness, and cohesiveness were lower in the Borisul group than in the Takju group due to a greater number of pores and surface cracks. Hardness, springiness, and cohesiveness values were highest at fermentation temperatures of 30, 35, and $40^{\circ}$C , respectively, in both groups, compared to samples at other temperatures. In the acceptance test, the Takju group was preferred over the Borisul group for appearance, texture, taste, flavor, and overall preference. There were also statistically significant preferences in taste, flavor, and overall preference for samples fermented at $40^{\circ}$C , in both groups, compared to those fermented at $30^{\circ}$C and $35^{\circ}$C. In the descriptive test, there were no differences in color according to fermentation agent and fermentation temperature, however, the Takju group was shinier than the Borisul group. In addition, the Takju group was harder and springier than the Borisul group, and had less sour taste and flavor than the Borisul group. Finally, in terms of overall preference, we found that Bori-sangoedduk made with Takju and fermented at $40^{\circ}$C for 3 hr was the best formula, due particularly to its taste and flavor.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.207-211
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• 1997

Media optimization for the production of thermostable protease specifically hydrolyzing defatted soybean meal (DSM) from Bacillus licheniformis NS70 was performed by two methods, one-at-a-time method and response surface methodology (RSM). The best carbon source and nitrogen source for the protease production were lactose and DSM, respectively. The maximum protease production estimated by RSM was 606 U/L at 1.11% lactose and 0.43% DSM, the value of which was nearly consistent to the experimental value of 599 U/L. Yeast extract suppressed the protease production. The medium pH was slightly increased at the beginning stage of fermentation, and it tended to decrease after 8 hours. The optimal pH for the protease production was 7.2 in the batch fermentation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.36-43
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• 2015

We examined sensory characteristics to determine the optimal conditions for flounder Verasper moseri Jordan et Gilbert sikhe preparation, using response surface methodology. Our aim was to develop the optimum mixing rates and materials for producing highly palatable flounder sikhe. The optimal fermentation temperature, salt concentration, and fermentation period for preparing flounder sikhe of acceptable quality were $11.63^{\circ}C$, 4.66% and 9.12 days, respectively. The optimal percentages of red pepper powder, garlic, monosodium glutamate, ginger, radish and foxtail millet were 16.08%, 7.21%, 2.96%, 3.70%, 10.12% and 13.72% respectively.

• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.299-304
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• 1986

The cell volume, cell surface, cell concentration, dry cell weight, frequence of respiratory deficient mutation, resistance against ultraviolet irradiation, fermentation power, DNA contents of haploid diploid, triploid and tetraploid of Saccharomyces cerevisiae strain were investigated. Respiratory deficient mutants by spontaneous mutation were absolved more frequently in the haploid than in the diploid, triploid and tetraploid. And cell volume, cell surface, cell concentration, dry cell weight, resistance against ultraviolet irradiation, fermentation power, and DNA contents were significantly increased as the ploidy increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.592-601
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• 2015

Rubus coreanus is known as Korean black raspberry, native to Korea, Japan, and China. Preliminary studies evaluating their potential for cancer treatment in mammalian test systems are ongoing. In recent years, interest has been renewed due to their high levels of anthocyanins. Anthocyanins in black raspberry are important due to their potential health benefits as dietary antioxidant, anti-inflammatory compound, and as a chemopreventive agent. In the present study, Saccharomyces cerevisiae BA29 was isolated from black raspberry fruit and fruit juice as a biogenic amine non-producing strain for manufacturing of black raspberry wine, after which we investigated its characteristics: biogenic amine-producing ability, cell growth ability, alcohol-fermentation ability, and resistance to alcohol, glucose, and sulfur dioxide. Based on preliminary experiments, we optimized culture medium compositions for improving dried cell weight of S. cerevisiae BA29 by response surface methodology (RSM) as a statistical method. Design for RSM used a central composite design, and molasses with the industrial applicability was used as a carbon source. Through statistical analysis, we obtained optimum values as follows: molasses 200 g/L, peptone 30 g/L, and yeast extract 40 g/L. For the model verification, we confirmed about 3-fold improvement of dried cell weight from 6.39 to 20.9167 g/L compared to basal yeast peptone dextrose medium. Finally, we manufactured black raspberry wine using S. cerevisiae BA29 and produced alcohol of 20.33%. In conclusion, S. cerevisiae isolated from black raspberry fruit and juices has a great potential in the fermentation of black raspberry wine.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.375-380
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• 2003

The study was carried out to set up alcohol fermentation condition for uncooked brown rice. Response surface methodology (RSM) was applied to optimize and monitor of the alcohol fermentation condition with uncooked brown rice. The primary variables were conducted the reaction surface regression analysis for the particle size of brown rice (20 40 60 mesh) the enzyme content (0.1,0.3,0.5%) and the agitating rate (0,100,200 rpm). Their optimization was 35~42 mesh for the size of particle and 0.32~0.43% for enzyme content by SAS (Statistical Analysis System). The coefficient of determination ($R^2$) in ingredients was admitted at the significant level of 5~10% in all ingredients except for a reducing sugar. Predicted values at optimum alcohol fermentation condition agreed with experimental values. During the fermentation, pH was decreased from 6.25 to 4.34, and total acidity was increased from 0.15 to 0.2. The amino acidity was decreased from 1.88 to 0.92, reducing sugar and total sugar contents were decreased 213 mg% and 1,077 mg%, respectively. Alcohol content was increased to 10% after 48 hr fermentation.

• Membrane Journal
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• v.23 no.4
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• pp.304-311
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• 2013

In fermentation-separation processes, nanofiltration membrane processes can be used to separate organic acid and other byproducts such as sugars and proteins. In this study, new nanofiltration membranes were prepared to improve organic acid permeability during the separation processes of fermentation broth. Positively charged nanofiltration membrane was introduced to reduce lactic acid rejection by electrostatic attraction between lactic acid and nanofiltration membrane. Newly fabricated nanofiltration membranes were prepared by grafting cationic polyelectrolyte, PEI, on membrane surface. Thenanofiltration membranes showed positively charged surface potential. As a result, lactic acid rejection was remarkably reduced while the rejection of glucose was not changed significantly.