• Food Science and Preservation
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• v.9 no.2
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• pp.179-183
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• 2002

This study was carried out to set up alcohol fermentation condition for uncooked corn. Response surface methodology(RSM) was applied to optimize and monitor the alcohol fermentation condition with uncooked corn. The optimal yeast strain for fermentation of uncooked corn was Saccharomyces cerevisiae GRJ. The polynomial equation for alcohol contents, brix, pH and total acidity showed 0.8852, 0.9202, 0.8806 and 0.9940 of R$^2$, respectively. The optimal rendition for maximum alcohol contents were 0.18%(w/w) of enzyme concentration and 180%(v/w) of added water content. Predicted values at optimum alcohol fermentation condition agreed with experimental value.

• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.317-323
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• 2022

Solid-state fermentation using hulled barley was carried out to produce enzymes and β-glucan. The one-factor-at-a-time experiments were carried out to determine the optimal composition of the basal medium. The modified synthetic medium composition in liquid-state fermentation was determined to be 70 g/l hulled barley, 0 g/l rice bran, 5 g/l soytone, and 6 g/l ascorbic acid. Optimal pretreatment conditions of hulled barley by solid-state fermentation were evaluated in terms of maximum production of fungal biomass, amylase, protease, and β-glucan, which were 1.26 mg/g, 31310.34 U/g, 2614.95 U/g, and 14.6% (w/w), respectively, at 60 min of pretreatment condition. Thus, the solid-state fermentation process was found to enhance the overall fermentation yields of hulled barley to produce high amounts of enzymes and β-glucan.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.739-744
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• 2008

The method of yeast propagation has an influence on yeast physiology, fermentation ability, flocculation rate, and taste stability of beer. In order to find optimal conditions for propagation, several parameters were investigated in combinations. The bottom brewing yeast grown at $10^{\circ}C$ indicated that a higher flocculation capacity during the $1^{st}$ fermentation. However, the taste stability and the aroma profile were not affected by parameters of propagation investigated. The beer quality was rather affected by storage duration. In addition, a correlation between tasting and chemiluminescence was found at the beer, which was produced using bottom brewing yeast. The propagation at $10-25^{\circ}C$ with addition of zinc ion indicated the best condition to improve fermentation ability, flocculation rate, and filterability for bottom brewing yeast, whereas the propagation at $30^{\circ}C$ with addition of zinc ion showed the best condition to increase fermentation ability for top brewing yeasts.

• YAKHAK HOEJI
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• v.38 no.6
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• pp.749-755
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• 1994

An interspecific fusant strain, Streptomyces MS1 was obtained by protoplast fusion between S. peucetius subsp. caesius and S. platensis. We studied on the fermentation characteristics of the fusant strain. The fermentation products of the fusant MS1 was identical with S. peucetius, but its production of anthracycline was more stable than S. peucetius under various fermentation conditions in regard to acidogenesis of fermentation broth. The optimal medium composition for anthracycline production by fusant MS1 as follows: sucrose 2.0%, glucose 1.0%, soytone 0.7%, $CaCO_3$ 0.2%, $KH_2PO_4$ 0.013%, casamino acids 0.01%, $K_2SO_4$ 0.025%, $MaCl_2\;6H_2O$ 1.024%, 5M $CaCl_2\;5H_2O$ 0.4%, 1N NaOH 0.7%, 20% L-proline 1.5%. In this condition, the productivity of anthracycline was $80{\sim}100\;{\mu}g/ml$.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.718-726
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• 2010

A selected fungal strain, for production of the raw-starchdigesting enzyme by solid-state fermentation, was improved by two repeated sequential exposures to ${\gamma}$-irradiation of $Co^{60}$, ultraviolet, and four repeated treatments with Nmethyl-N'-nitrosoguanidine. The mutant strain Aspergillus sp. XN15 was chosen after a rigorous screening process, with its production of the raw-starch-digesting enzyme being twice that of usual wild varieties cultured under preoptimized conditions and in an unsupplemented medium. After 17 successive subculturings, the enzyme production of the mutant was stable. Optimal conditions for the production of the enzyme by solid-state fermentation, using wheat bran as the substrate, were accomplished for the mutant Aspergillus sp. XN15. With the optimal fermentation conditions, and a solid medium supplemented with nitrogen sources of 1% urea and 1% $NH_4NO_3$, 2.5 mM $CoSO_4$, 0.05% (v/w) Tween 80, and 1% glucose, the mutant Aspergillus sp. XN15 produced the raw-starch-digesting enzyme in quantities 19.4 times greater than a typical wild variety. Finally, XN15, through simultaneous saccharification and fermentation of a raw rice corn starch slurry, produced a high level of ethanol with $Y_{p/s}$ of 0.47 g/g.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.689-695
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• 2013

Flounder Verasper moseri Jordan et Gilberu sikhae is a traditional salt-fermented food in Korea. We investigated the optimal processing conditions for desirable quality-controlled flounder sikhae by analyzing the physiochemical properties, microbiological species, and organoleptic properties. The optimal fermentation temperature, salt concentration, and fermentation period for preparing flounder sikhae of acceptable quality were $10^{\circ}C$, 4%, and 14 days, respectively. The amino-N and volatile basic nitrogen (VBN) contents of rhe acceptable quality flounder sikhae were 243.65 mg/100 g and 44.25 mg/100 g, respectively.

• KSBB Journal
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• v.30 no.1
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• pp.33-37
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• 2015

Recently, several health benefits of rice wine, makgeolli, were known due to the interest on the traditional Korean liquor and the researches on the rice wine are increasing. Organic acids produced during the process of rice wine fermentation play important roles in the taste and flavor. In this study, we have examined the optimal conditions for lactic acid production in rice koji as a carbon source. Skim milk was also used as a supplementary ingredient for the optimization of lactic acid fermentation. Bacterial growth of Lactobacillus sakei was monitored under this condition. The pH, acidity of the culture and the ethanol tolerance of this bacterium were also tested. Through these experiments, we were able to optimize the growth condition of lactic acid bacteria by the addition of skim milk. This was also able to affect the change of pH, acidity, sugar concentration and alcohol tolerance, which might contribute to the improvement of the quality of rice wine. The optimal condition for the growth was 2 days with 10% (w/v) of skim milk concentration. With these results, it was confirmed that rice koji was an effective carbon source for the growth of lactic acid bacteria.

• Applied Biological Chemistry
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• v.51 no.1
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• pp.17-23
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• 2008

In order to prevent wine quality deterioration caused by strong sour taste from raw and other materials during fermentation of wild grape wine, the various mixed cultures conditions of the deacidification fermentation and the alcohol fermentation process by inoculation of mixed strains were investigated. As a result of mixed cultures process after the inoculation of Schizosaccharomyces pombe and Schizosaccharomyces japonicus with each deacidification fermentation strain in a culture of Saccharomyces sp. SMR-3 which was used in the alcohol fermentation strain of wild grape, cultures for 12 days at $22^{\circ}C$ with Saccharomyces sp. SMR-3 and Schizosaccharomyces pombe resulted in the maximum alcohol content at $15.8{\pm}0.2%$ and the minimum with the acidity of $0.44{\pm}0.02%$, the total organic acid of $648.96{\pm}7.14$ mg% and malic acid of $99.30{\pm}1.24$ mg%. Mixed cultures with Saccharomyces sp. SMR-3 and Schizosaccharomyces pombe under the optimal condition for the deacidification fermentation of wild grape wine showed 2% higher alcohol content, 51.65% lower acidity, 48.02% lower total organic acid, and 81.12% lower malic acid than a single culture of Saccharomyces sp. SMR-3.

• International Journal of Industrial Entomology and Biomaterials
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• v.34 no.2
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• pp.38-44
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• 2017

Mulberry leaves containing 1-deoxynojirimycin (DNJ) have been recognized as a potentially important source for prevent or treat hyperglycemia. However, DNJ content of natural mulberry leaf are as low as 0.1%. Thus, the most effective method for increasing ${\alpha}$-glucosidase inhibitory activity with the DNJ high-production is needed. In this study, we investigated the influence of ${\alpha}$-glucosidase inhibitory activity according to different pH values (6-9) and inoculation amounts (0.1-0.5%) when Bacillus subtilis cultured on mulberry leaf powder media. We confirmed that ${\alpha}$-glucosidase inhibitory activity was difference according to culture conditions of different pH values, inoculation amounts, and fermentation times. The results of mulberry leaf fermentation according to pH values and inoculation amounts were shown that the optimal conditions for ${\alpha}$-glucosidase inhibitory activity were defined as pH 7 and 9, inoculation amount 0.4%, and incubation until 2 to 4 days. These results can be provided a basic data for the optimal culture conditions increasing ${\alpha}$-glucosidase inhibitory activity from mulberry leaf fermentation.

• Food Science and Biotechnology
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• v.14 no.5
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• pp.561-565
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• 2005

In this study, we attempted to assess the effects of lactate and com steep liquor (CSL) on the production of bacterial cellulose (BC) by Gluconacetobacter persimmonis $KJ145^T$. The optimal condition for the production of BC was a lactate concentration of 1% (w/v) and a CSL concentration of 10% (w/v). Under these optimal conditions, 6 days of fermentation produced 6.90 g/L of BC. Both the BC production yield and cell growth increased continuously until the 20th day of fermentation, by which time 17.0 g/L had been produced. In a static culture trial, in which plastic containers were used as fermentation chambers for 6 days of fermentation, the BC production yield in the group initially cultured with 500 mL medium was higher than that of the 750 and 1000 mL media. In addition, the texture of the BC was examined according to its post-treatment in order to determine conditions for optimal textural characteristics. The strength, hardness, and other characteristics of the BC were negatively correlated with sucrose concentration, but were largely positively correlated with NaCl concentration. With regards to the effect of pH on textural change, BC strength and hardness were elevated at pH 2 and 8 but reduced at pH 4 and 6, indicating that the texture of the BC is extremely sensitive to treatment conditions.