• 한국생물공학회:학술대회논문집
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• 2002.04a
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• pp.184-187
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• 2002

Lovastatin is a cholesterol-lowering agent, which plays a role of an inhibitor of 3-hydroxy-3- methylglutaryl coenzyme A reductase (HMG-CoA). When thiamine was supplemented in 3L batch fermentation, the production of lovastatin was improved. At the same time, the levels of pyruvic acid and NAD(P)H were estimated in the course of the fermentation of A. terreus. For the high level production of lovastatin, semi fed-batch fermentation was performed. And the thiamine level was maintained to a concentration of 20 mg/L and glucose was supplied. The final dry cell weight was lowered by 30 % and final lovastatin concentration was increased by 33 %. Final lovastatin concentration of 3.3 g/L was achieved in 8 days.

• Mycobiology
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• v.36 no.3
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• pp.183-189
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• 2008

The production of aerial conidia of Lecanicillium lecanii 41185, a highly virulent fungus, by solid-state fermentation was studied for use as a biocontrol agent against aphids. Among several agro-industrial solid media, steamed polished rice was found to produce the highest amount of aerial conidia. The optimal conditions for aerial conidia production were determined to be a 28.5% moisture content in the rice, 25$^{\circ}C$ culture temperature, rice pH of 6.0, 75% ambient relative humidity, 4-dold seeding culture, 0.6% $KNO_3$, and 12 d of culture time. The conidia yield increased from $5.7\times10^9$ conidia/g polished rice to 18.2 $18.2\times10^9$ conidia/g polished rice following application of these optimized conditions.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.110-116
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• 2010

Lactic acid (LA) fermentation by Lactobacillus salivarius ATCC 11741 immobilized on loofa sponge (LS) was evaluated. To increase the surface area of LS for cell immobilization, $H_2O_2$ and chitosan were introduced as surface modifying reagents. Four chitosans of different molecular weights were separately coated on LS. All experiments were conducted in shaking flask mode at 100 rpm rotating speed and $37^{\circ}C$ with 5% $CaCO_3$ as a pH regulating agent. The effects of initial glucose concentration were investigated in the range of 20-100 g/l on LA fermentation by free cells. The results indicate that the maximum concentration of LA was produced with 50 g/l glucose concentration. The immobilized cell system produced 1.5 times higher concentration than free cells for 24 h of fermentation. Moreover, immobilized cells can shorten the fermentation time by 2-fold compared with free cells at the same level of LA concentration. At 1% (w/v) chitosan in 2% (v/v) acetic acid, the Yp/s and productivities of various molecular weights of chitosans were insignificantly different. Repeated batch fermentations showed 5 effective recycles with Yp/s and productivity in the range of 0.55-0.85 and 0.90-1.20 g/l.h, respectively. It is evident that immobilization of L. salivarius onto LS permits reuse of the system under these fermentation conditions. Scanning electron micrographs indicated that there were more intact cells on the chitosan-treated LS than on the untreated LS, thus confirming the effectiveness of the LS-chitosan combination when being utilized as a promising immobilization carrier for LA fermentation.

• Journal of the Korean Society of Food Culture
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• v.37 no.6
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• pp.555-563
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• 2022

The purpose of this study was to confirm the quality characteristics of distilled soju with different rice pretreatment processes. The non-steamed fermentation method is a technology that uses starch to produce saccharification and alcohol without going through the steaming of raw materials. It has advantages such as reduction of manpower and cost, prevention of nutrient loss, and minimization of waste water. In this study, rice used were non-steamed and pulverized 'Baromi2', nonsteamed and steamed 'Samgwang', and puffed rice. As the fermenting agent, koji, modified nuruk, N9 yeast, and purified enzyme were used, and lactic acid was added to prevent contamination during fermentation. The amount of water was 300% in total, and after the first watering, 5 days after fermentation, the second watering was carried out. As a result of the study, it was confirmed that the non-steamed fermentation method using 'Baromi' was superior to the existing fermentation method in terms of temperature during fermentation, final alcohol content, soluble solids, and pH. By expanding the stability of the production technology of non-steamed fermentation technology, product quality improvement can be expected.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.84-86
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• 2014

Mass production of biocontrol agent is an essential step for its commercial use. Media composition and culture conditions for production of Bacillus amyloliquefaciens SKU-78, a potential biocontrol agent against bacterial wilts, were optimized by a flask culture. Low cost media combining nitrogen and carbon sources were tested. Maximum cell growth (> $2{\times}10^9$ CFU/ml) was obtained in a medium of 5% soy flour combined with 3% corn starch after 24 h cultivation. The optimum initial pH, temperature and shaking speed was 5.5, $30^{\circ}C$ and 150-250 rpm, respectively. Fermentation of SKU-78 was scaled up in 30 L fermenter and the profiles of cell density, pH, dissolved oxygen and spore formation were recorded. After 8 h lag phase, exponential growth occurred and reached at maximum viable cell number ($1.2{\times}10^{11}$ CFU/ml) after 20 h. The SKU-78 strain grown in a low cost medium exhibited the high suppression of bacterial wilts. The results indicate that SKU-78 strain can be produced in a low cost medium and provide a basis for scaling up to industrial level.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.427-440
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• 1998

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.96-104
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• 2009

Three kinds of grape yakju (Kyoho, Campbell and Moru) and grape-free control were fermented with rice using koji of Aspergillus kawachii as a fermenting agent, and their fermentation characteristics were investigated. For the three yakju, reducing sugar content decreased slowly over 2 days fermentation after an initial rapid decrease. In case of Brix, the reducing sugar content increased gradually after increasing rapidly during the first 2 days of fermentation. The Kyoho and Moru groups displayed a gradual increase in reducing sugar content after an initial 2-day decrease, and the sugar content of the Campbell group increased gradually during fermentation. Uniformly, pH increased gradually after an initial 2-day decrease, however total acid increased continuously throughout fermentation. Alcohol content of yakju showed almost no change after increasing until day 6 (Kyoho) of day 4 (others), with the control displaying the highest content. Control $\alpha$-amylase activity decreased gradually after an initial 2-day increase, while that of the three yakju decreased throughout fermentation. Activities of $\beta$-amylase activities paralleled the results of reducing sugar. Concerning total anthocyanin, the Moru and Campbell groups displayed a rapid increase until day 2, a decrease until day 12, and a gradual increase thereafter. While the Kyoho and control groups displayed virtually no change after an initial 2-day increase until day 12, after which a gradual increase also occurred. In concerning sensory evaluation, Moru yakju scored highest for violetness, flavor of grape, and sweet taste, and also displayed a low alcohol content. These attributed Moru yakju the preferred choice.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.808-816
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• 2022

This study was conducted with a view toward enhancing the industrial utilization of a male sailfin sandfish Arctoscopus japonicus based on its application in the preparation of Sik-hae, a Korean traditional fermented fishery product prepared using hard-boiled rice and enzymatic malt sprouts. As an alternative to rice and malt sprouts, we evaluated the utility of rice Koji for Sik-hae fermentation by investigating the physicochemical changes that occur during fermentation. The sailfin sand fish Sik-hae fermented with 10% or 20% rice Koji was found to show similar fermentation characteristics to the control fermentation with 20% hard-boiled rice and 4% malt sprouts, with respect to acid production, texture profile, and the softening of bones during the entire fermentation period. In particular, compared with the control, the addition of 10% rice Koji reduced the dehydration of Sik-hae and increased the content of free amino acids, which contributed to preventing a marked reduction in pH during fermentation. Accordingly, 10% rice Koji is proposed as a viable alternative enzymatic agent for the preparation of Sik-hae, which can contribute enhancing the desired properties of this traditional food product.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.4
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• pp.602-609
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• 2002

Lao-chao is a traditional Chinese fermented rice product with a sweet and fruity flavor, containing high levels of glucose, a little alcohol and milk-clotting characteristics. In order to optimize commercial production of lao-chao, Rhizopus javanicus and Saccharomyces cerevisiae were selected as the mold and yeast starter, respectively. A commercial mixed starter (chiu-yao) was used as control. Fermentation of the experimental combination revealed a sharp drop in pH (to 4.5) on the fourth day, remaining constant thereafter. Content of reducing sugars gradually decreased throughout the entire fermentation period. Of the free amino acids, higher quantities of alanine, leucine, proline, glutamic acid, glutamine and $NH_3$ were noted. For sugars, glucose revealed the highest concentration, while organic acid levels, including those for oxalic, lactic, citric and pyroglutamic acid, increased throughout the fermentation period. Twenty-one compounds were identified by gas chromatography from aroma concentrates of the lao-chao culture filtrate, prepared using the headspace method. For the flavor components, higher quantities of ethanol, fusel oil and ester were determined in both culture filtrates. In regard to the evaluation of yogurt-like product, there were significant differences in alcoholic smell, texture and curd firmness.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1063-1066
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• 2016

Longan (Dimocarpus longan Lour.) has been used as a traditional oriental medicine and possesses a number of physiological activities. In this study, we used cell-based herbal extract screening to identify longan fruit extract (LFE) as an activator of osteoblast differentiation. LFE up-regulated alkaline phosphatase (ALP) activity, induced mineralization, and activated Runx2 gene expression in MC3T3-E1 cells. Furthermore, treatment of MC3T3-E1 cells with LFE promoted the phosphorylation of extracellular signal-regulated kinase1/2 (Erk1/2); however, abrogation of Erk1/2 activation with PD98059 resulted in down-regulation of the phospho-SMAD1/5/8 and Runx2 levels, which in turn reduced the ALP activity. Our findings suggest that LFE exerts its osteogenic activity through activation of the ERK signaling pathway and may have potential as an herbal therapeutic or a preventive agent for the treatment of osteoporosis.