• KSBB Journal
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• v.15 no.1
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• pp.88-95
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• 2000

We have produced new-structured oligosaccharides using immoobilized mixed-enzyme reactor of destransucrase from Leuconostoc mesenteroides B-512FMCM and $\alpha$-amylase from Aspergillus oryzae. The reactors of immobilized mixed-exzyme beads were more efficient for the production of oligosaccharides than that of each immobilized enzyme bead in stirred-tank reactior(STR) or in packed-bed reactor(PCR). In continuous flow reactor, the immobilized mixed-enzyme bead in PBR was more stable than in STR, and 52% of initial yield was maintained for 200 hr. New structured-oligosaccharides (NOS) reduced the change of pH in the culture of Streptococcus mutans. It also showed an inhibitory effect on the growth of Staphylococcus aureus.

• Korean journal of applied entomology
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• v.13 no.2 s.19
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• pp.71-75
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• 1974

A study was conducted to investigate the relationships between the rice weevil and associated storage molds. The results are as follows; 1. All of the developmental stages of the rice weevils are carrying some storage molds in their bodies, and the order of magnitute in the number was the adult, larva and pupa. 2. The molds persist in the body of the rice weevil for 10 days who.1 they were fed on the mold free wheat, and the most persistant mold species was A. candidus. 3. When the mold free weevils were reared on the pure culture of the molds on the wheat, the number of eggs laid by the Lveevil were the greatest for A. candidus. following A. ruber, and the . least number Lvere obtained with A. niger 4. The rice weevil could complete in the pure mold culture on the wheat except for A. niger where the larvae had developed by 2nd or 3rd instars. 3. The shortest developmental periods was obtained with A. candidus and the first adult emerged in 4th week. 6. The unfavorable effects of A. niger on the development of the rice weevil might be associated with the fast growth of the mold together with some unknown effects. 7. There seems to be a protocooperative interaction between these two oraganisms having been developed through the long evolutionary course in common habitat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.75-80
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• 2002

The growth inhibition by nisin-Producing lactococci against Bacillus subtilis and its application to doenjang fermentation were investigated. Lactococcus lactis subsp. lactis IFO 12007, L. lactis subsp. lactis ATCC 7962 and L. lactis subsp. lactis ATCC 11454 were used as nisin-producing lactococci. All of three strain rapidly proliferated to more than 10$^{9}$ CFU/g in steamed soybeans. Only L. lactis subsp. lactis IFO 12007 was in steamed soybean without any pH decrease. In spite of the mild decrease in pH, the growth of B. subtilis was completely inhibited; no living cells were detected in a soybean sample inoculated with 10$^{6}$ CFU/g and incubated for 24 to 72h. The L. lactis subsp. lactis IFO 12007 was applied to doenjang fermentation as a starter culture. It produced high nisin activity in steamed soybean, resulting in the complete growth inhibition of B. subtilis, which had been inoculated at the beginning of the meju fermentation, throughout the process of doenjang production. Over-acidification, which is undesirable for doenjang quality, was successfully prevented simply by adding salt which killed the salt-intolerant L. lactis subsp. lactis IFO 12007. Furthermore, the nisin activity in doenjang disappeared with aging.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.237-241
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• 1992

The protease from Halomonas sp. ES 10 was purified by methanol precipitation, gel filtration on Sephadex G-150 and G-200, and ion exchange chromatography on DEAE-Sephadex A-50. The purified enzyme was found to be homogeneous by polyacrylamide gel electrophoresis. The specific activity of purified enzyme was 1,014 units/mg protein, and the yield of the total activity from the culture filtrate was 7%. The optimal temperature and pH for the enzyme activity were $35^{\circ}C$, and pH 11.0, respectively. And the enzyme was stable in the range of $pH\;7.5{\sim}11.0$. The residual activity of the enzyme was 70%, when the enzyme was incubated at $50^{\circ}C$ for 40 min. The Km value of the enzyme was 7.4 mg/ml to milk casein. $Li^+$, $Ca^{2+}$, SDS and Tween 80 were appeared to activators, whereas $Hg^{2+}$ and EDTA to inhibitors. The addition of DFP and PMSF showed the relative enzyme activities of 63% and 107%, respectively, suggesting that the enzyme may not belong to serine type protease. When the alkaline protease was treated with 0.5 M and 1 M NaCl, the relative enzyme activities were 95% and 65%, respectively. This enzyme showed 20% and 15% higher enzyme activity than that of Aspergillus oryzae (Sigma Chemical Company product, P4755) in the presence of 0.5 M and 1 M NaCl.

• Journal of Applied Biological Chemistry
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• v.52 no.3
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• pp.133-141
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• 2009

This study was carried out in order to investigate the changes in chemical components of four kinds of Cheonggukjang during fermentation. Three different kinds of Cheonggukjang were prepared with germinated soybeans using rice straw, Bacillus natto, Bacillus natto plus Aspergillus oryzae, and non-germinated soybeans using rice straw. The nitrogen contents increased significantly during fermentation in all kinds of Cheonggukjang. Especially germinated soybean Cheonggukjang prepared with A. oryzae plus B. natto showed approximately 1.3 to 3.0 fold higher values than the other Cheonggukjangs. Total free amino acid contents of all Cheonggukjangs increased with an increase in fermentation time until 60 h. Lysine content was highest in Cheonggukjang prepared with ungerminated soybean at 72 h of fermentation. Among free amino acids of germinated soybean Cheonggukjang prepared with rice straw, glutamic acid was highest (3.64 mg/g) after 72 h of fermentation. In Cheonggukjang prepared with mixed culture, glutamic acid content was 4.37 mg/g. Total carbohydrate contents of Cheonggukjang decreased rapidly with an increase in fermentation time except the ungerminated soybean Cheonggukjang, and the total carbohydrate contents varied from 9.81 to 14.04% after 72 h of fermentation. On the other hand, total carbohydrate contents of ungerminated soybean Cheonggukjang prepared with rice straw gradually decreased during fermentation. In conclusion, it is expected to increase the contents of functional constituents and to improve quality characteristics of Cheonggukjang when it is prepared with germinated soybeans using B. natto plus A. oryaze.