• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 1993.05a
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• pp.149-159
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• 1993

The concept of Solid-State Fermentation is briefly explained in comparison to other fermentation principles, and several types of fermenters are presented. A recently developed "Swing Reactor" for SSF is shown. When inoculated on rice, the mould Monascus purpureus forms red pigments, Which can be used as food colors (Ang-kak, Red Rice). By Response Surface Methodology, serveral factors have been optimized for maximal red colour formation. Showing that presoaking time of rice, pH of soaking water, age of preculture and inoculum size were not of importance within the observed limits. For a fermentation time of 7 days, start humidity is optimal at 34% and temperature is optimal at 28.8 C. These results of small scale fermentation could be transferred to the Swing Reactor.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.107.1-107
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• 2003

The fermentation process and subsequent processing determine the efficacy of a bioherbicide propagule. Large batches of biomass of the mycoherbicide agent for white clover, Sclerotium sp.(BWC98-105) was produced in simple liquid fermentator in 5 gallons vessels(Model No. 8087, Dabo Inc., Korea) with oxygen supply(DPH16000, FineTech Inc., Korea) simulating industrial conditions by utilizing commercially available, inexpensive ingredients (10 ％ rice bran), The maximum biomass yield of Sclerotium sp.(BWC98-105) was obtained after 5 days of air pumped incubation at room temperature condition(22-28$^{\circ}C$). By using this simple facility, it could get fragmented or proliferated greatly and attained maximum mycelia biomass. The biomass of mycoherbicide agent consisted of hyphae devoid of spores. Biomass mycelia of the fungus 99％ survival at room temperature after 2 me. A thorough understanding of the effects of fermentation and formulation on viability and virulence is required to guide these processes. After an economical yield level of bioherbicide propagule has been achieved in a fermentation process, formulation becomes a critical factor which influences product efficacy. Because the fermentation must be stopped at a point when virulence/viability are optimum, the live bioherbicide propagule must be stabilized, formulated, and packaged.

• Journal of Microbiology and Biotechnology
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• v.16 no.12
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• pp.1849-1855
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• 2006

It has been shown that the initial conditions of bacterial cultivation are extremely important for the successful production of hyaluronic acid (HA) by fermentation. We investigated several parameters that affect cell growth rate and the productivity and molecular weight of hyaluronic acid--i.e., agitation speed, aeration rate, culture temperature, pH, and pressure--to determine how to optimize the production of HA by Streptococcus zooepidemicus on an industrial scale. Using a 30-1 jar fermentor under laboratory conditions, we achieved maximum HA productivity and biomass when the agitation speed and aeration rate were increased simultaneously. By shifting the temperature downward from 35$^{\circ}C$ to 32$^{\circ}C$ at key levels of cell growth during the fermentation process, we were able to obtain HA with a molecular weight of $2.8{\times}10^6$ at a productivity of 5.3 g/l. Moreover, we reproduced these optimized conditions successfully in three 30-1 jar fermentors. By reproducing these conditions in a 3-$m^3$ fermentor, we were able to produce HA with a molecular weight of $2.9{\times}10^6$ at a productivity of 5.4 g/l under large-scale conditions.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1253-1259
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• 2013

The influences of glucose concentration, initial medium acidity (pH), and temperature on the growth and ethanol production of Saccharomyces cerevisiae NK28, which was isolated from kiwi fruit, were examined in shake flask cultures. The optimal glucose concentration, initial medium pH, and temperature for ethanol production were 200 g/l, pH 6.0, and $35^{\circ}C$, respectively. Under this growth condition, S. cerevisiae NK28 produced $98.9{\pm}5.67$ g/l ethanol in 24 h with a volumetric ethanol production rate of $4.12{\pm}0.24g/l{\cdot}h$. S. cerevisiae NK28 was more tolerant to heat and ethanol than laboratory strain S. cerevisiae BY4742, and its tolerance to ethanol and fermentation inhibitors was comparable to that of an ethanologen, S. cerevisiae D5A.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.3
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• pp.9-14
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• 2012

Formed fermentation inhibitors during acid saccharification leads to poor alcohol production based on lignocellulosic bio-alcohol production process. In this work, it is focused on the formation of fermentation inhibitors from xylan, which is influenced by reaction tempearature and time of acidic sacharifiaction of xylose and glucuronic acid. In second step of concentrated acid hydrolysis, part of xylose and glucuronic acid was converted to furfuraldehyde and formic acid by dehydration and rearrangement reactions. Furfural was form from xylose, which was highly sensitive to reaction temperature. Formic acid was come from both xylose and glucuronic acid, which supposed to main inhibitor in biobutanol fermentation. Reaction temperature of second hydrolysis was main variables to control the furfural and formic acid generation. Careful control of acid saccharification can reduce generation of harmful inhibitors, especially second step of concentrated sulfuric acid hydrolysis process.

• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.489-498
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• 2013

A new Bacillus strain degrading starch, named Bacillus sp. UEB-S, was isolated from a southern Tunisian area. Amylase production using solid-state fermentation on millet, an inexpensive and available agro-resource, was investigated. Response surface methodology was applied to establish the relationship between enzyme production and four variables: inoculum size, moisture-to-millet ratio, temperature, and fermentation duration. The maximum enzyme activity recovered was 680 U/g of dry substrate when using $1.38{\times}10^9$ CFU/g as inoculation level, 5.6:1 (ml/g) as moisture ratio (86%), for 4 days of cultivation at $37^{\circ}C$, which was in perfect agreement with the predicted model value. Amylase was purified by Q-Sepharose anion-exchange and Sephacryl S-200 gel filtration chromatography with a 14-fold increase in specific activity. Its molecular mass was estimated at 130 kDa. The enzyme showed maximal activity at pH 5 and $70^{\circ}C$, and efficiently hydrolyzed starch to yield glucose and maltose as end products. The enzyme proved its efficiency for digesting raw cereal below gelatinization temperature and, hence, its potentiality to be used in industrial processes.

• Food Science and Preservation
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• v.19 no.1
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• pp.144-152
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• 2012

The temperature changes and quality characteristics of $Makgeolli$ produced using rice treated with $Gaeryang-Nuruk$ (commercial improved $Nuruk$) extract were investigated. During fermentation, the treated rice maintained a lower temperature than the control and then rose after the fifth mashing day. For all the treatments, the numbers of yeast, LAB and AAB colonies increased on the second mashing day, and then gradually decreased. As the fermentation proceeded, the pH gradually increased from the third mashing day, and eventually became higher than that on the initial mashing day. The total acid contents increased on the first mashing day, but as the fermentation progressed, they showed little change. The amino acidity and soluble solid contents during overall fermentation and reducing-sugar contents was reduced until the first mashing day, and increased from the day after. As for the alcohol content, that of the control was 6.87% on the first mashing day, and then gradually increased, nuruk-extract-treated rice began with 9~10% alcohol content and then increased as the fermentation proceeded. Among the organic acid contents, lactate was the main material. In the sensory evaluation, the 24 h-, 48 h- and 72 h- treated rice samples showed somewhat good response.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.6
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• pp.832-840
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• 2014

This study aimed to investigate the effects of storage duration and temperature on the characteristics of wet brewers grains (WBG) as feeds for ruminant animals. Four storage temperatures ($5^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$) and four durations (0, 1, 2, and 3 d) were arranged in a $4{\times}4$ factorial design. Surface spoilage, chemical composition and microorganism density were analyzed. An in vitro gas test was also conducted to determine the pH, ammonia-nitrogen and volatile fatty acid (VFA) concentrations after 24 h incubation. Surface spoilage was apparent at higher temperatures such as $25^{\circ}C$ and $35^{\circ}C$. Nutrients contents decreased concomitantly with prolonged storage times (p<0.01) and increasing temperatures (p<0.01). The amount of yeast and mold increased (p<0.05) with increasing storage times and temperatures. As storage temperature increased, gas production, in vitro disappearance of organic matter, pH, ammonia nitrogen and total VFA from the WBG in the rumen decreased (p<0.01). Our results indicate that lower storage temperature promotes longer beneficial use period. However, when storage temperature exceeds $35^{\circ}C$, WBG should be used within a day to prevent impairment of rumen fermentation in the subtropics such as Southeast China, where the temperature is typically above $35^{\circ}C$ during summer.

• Korean journal of food and cookery science
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• v.13 no.5
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• pp.578-584
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• 1997

Fermentation temperature and salt concentration of Dongchimi were studied for the development of low salt Dongchimi juice. The juice was prepared by soaking the radish in brine solution of 0.3∼3.0% and fermented at the temperature range of 10∼30$^{\circ}C$. The fermentation proceeded faster at higher temperature. However, the salt concentration effect was dependent on the temperature. Fermentation in 3.0% NaCl solution resulted the fastest reach to pH 3.8 followed by 0.5% NaCl at 10 and 20$^{\circ}C$, while higher NaCl concentration caused a decrease in the fermentation rate at 30$^{\circ}C$. Comparison of flavor of the juice of pH 3.9 showed that fresh sourness was high in the juice prepared at 20$^{\circ}C$ and in 0.5% NaCl. The preference test also showed the juice of pH 3.8∼4.0 fermented in 0.5% NaCl at 20$^{\circ}C$ to be the most preferable one. The salt concentration lower than 0.5% at 20$^{\circ}C$ resulted in faster fermentation and high values in turbidity. However 0.5% NaCl was scored high in flavor acceptability.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.25-33
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• 1984

This experiment carried out to obtain the thermophilic yeast, suitable for ethanol fermentation, and two usable strain were isolated. And microbial characteristics of these strains were investigated, and ethanol fermentation tested. The results obtained were as follows; 1. The selected yeasts were identified D-71 with Saccharomyces cerevisiae, and J-515 with Saccharomyces fermentati. 2. The strains D-71 and J-515 were showed the highest ethanol fermentation activity in the crushed corn mash of high concentration at $35^{\circ}C$, and showed the slightly lower at $40^{\circ}C$ than in the case of $35^{\circ}C$. 3. The strains D-71 and J-515 were showed the very higher ethanol fermentation activity than that of compared strain at $35^{\circ}C$ and $40^{\circ}C$, and at these temperature, fermentation period was a little bit of short. 4. On fermentation test using D-71 and J-515, the residual total sugar in the mash was very lower at $35^{\circ}C$.