• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.839-843
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• 2001

The effect of gamma-irradiation on the hydrolytic enzyme activities of some Koran soybean-based fermented foods was studied. Doenjang (soybean paste), kanjang (soy sauce), kochujang (red pepper paste), chungkukjang and meju were prepared and irradiated at 0, 5, 10 and 20 kGy. Then activities of protease, amylase, lipase and fibrinolytic enzyme were determined. Hydrolytic enzyme activities of meju, chungkukjang and doenjang were relatively higher than those of kanjang and kochujang. Amylase, protease and lipase activities were not affected by 10 kGy and were slightly (about 10%) inactivated by 20 kGy of gamma irradiation, with no statistical significance. Fibrinolytic enzyme was stable in all treatments.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.133-139
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• 2012

A bacterium, identified as $Bacillus$ $amyloliquefacies$, CNL-90 using 16S rDNA analysis, was isolated from malt grain. The optimal activities of its ${\alpha}$-amylase and protease were observed at pH 6 and $60^{\circ}C$, and at pH 6 and $50^{\circ}C$, respectively although their activities remained stable at pH 7 and $40^{\circ}C$for ${\alpha}$-amylase and at pH 7 and $50^{\circ}C$ for protease. After solid-state fermentation of $B.$ $amyloliquefacies$, CNL-90 on wheat bran for 72hr or 144hr, the ${\alpha}$-amylase and protease activities were 170,000 and 290,000 units/kg, and 290,000 and 310,000 units/kg, respectively. The viable bacterial cell counts were $1.5{\times}10^9$ CFU/g and $2.2{\times}10^9$ CFU/g at 72hr and 144hr of the solid-state fermentation, respectively. A feeding trial with a total of 127 piglets was also conducted. The animals were divided into two groups: an experimental group fed with the fermented product (63 piglets) and a control group (64 piglets). The growth rate of the experimental group was 6.66% higher than that of the control group (P<0.05). The results of this study indicate that the ${\alpha}$-amylase and protease from $B.$ $amyloliquefacies$, CNL-90 can be used for industrial applications due to their activity in production of carbohydrate hydrolysates.

• Korean Journal of Microbiology
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• v.40 no.3
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• pp.230-231
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• 2004

The mycelia of Sparassis crispa DSMZ 5201 were cultivated at $24^{\circ}C$ for 15 days in yeast-malt extract-glucose broth (pH 4.0) and the filtrate was used as crude enzyme solution to determined the extracellular enzyme activity. The specific activity of $\alpha$-amylase was 44.27 unit/protein. The specific activities of protease, CMCase, $\beta$-glucosidase, chitinase, exo-$\beta$-l,4-glucanase were relatively high. However, a very little activity of xylanase was found.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.369-375
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• 2018

This study investigated the effects of selected seaweeds on rice koji preparation (rice inoculated with Aspergillus luchuensis) and enzyme activity. Four types of rice koji were prepared using one of three seaweeds (0.5% laver, 0.5% kelp and 0.5% green laver) or a control for 72 h. The changes in the moisture content, water activity, pH, total mold cell count, amylase and protease activities were measured. During preparation, there was no significant difference in the moisture content among the four kojis, whereas the pH in the kojis made with either laver or green laver decreased rapidly compared with the control (P<0.05). This seemed to result from the seaweeds promoting the growth of mold cells. In terms of the activities of both amylase and protease, the koji with laver was superior. Subsequently, the amylase and protease activities of the koji made with laver were evaluated at various pHs (3 to 9), temperatures ($15-55^{\circ}C$) and NaCl concentrations (0-10%). The activities of both enzymes decreased notably at pH 9 and the protease activity decreased at temperatures above $45^{\circ}C$. Although the activities of both enzymes decreased at greater than 2.5% NaCl, activity was present at 10% NaCl.

• Journal of Mushroom
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• v.8 no.3
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• pp.102-108
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• 2010

In this study, growth rates and enzyme activities of mushroom mycelium were investigated in each cereals. Cultivation on hulled barley resulted in slightly faster mycelial growth as compared to other substrates. Enzyme activities were measured in different periods. In result, ${\alpha}$-amylase activity was higher in Pleurotus ostreatus and Phellinus linteus cultured cereals, whereas ${\beta}$-amylase activity was higher in Pleurotus ostreatus and Fomitella fraxinea cultured. Protease level did not affect kinds of cereal except Phellinus linteus. The color values lightness decrease by Basidiomycetes cultivation and redness and yellowness increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.11 no.2
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• pp.1-6
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• 1982

The constituents of sugar, enzyme activity and number of pollens in standard honey (gathered from my own honey comb.) and commercial ones collected from local markets) were determined to know the difference between above two kinds of honey. The results obtained were as follows. 1. The constitution of saccharides in commercial honey was higher at 1% than the standard one. The average content showed 45% of fructose,41% of glucose, 3% of dextrin and 2% of sucrose. 2. Pollen contained in honey were mainly composed of oval and globe shape. The nunlber of pollen contained in standard honey was five times more than that in commercial ones .3. ${\alpha}-amylase$, ${\beta}-amylase$ and protease activity of standard honey were greated 5,2,2 times respectively comparing with that of commercial one, and acid protease activity with each sample was higher than the neutral.

• Mycobiology
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• v.39 no.2
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• pp.118-120
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• 2011

The ability of Ganoderma to produce extracellular enzymes, including ${\beta}$-glucosidase, cellulase, avicelase, pectinase, xylanase, protease, amylase, and ligninase was tested in chromogenic media. ${\beta}$-glucosidase showed the highest activity, among the eight tested enzymes. In particular, Ganoderma neo-japonicum showed significantly stronger activity for ${\beta}$-glucosidase than that of the other enzymes. Two Ganoderma lucidum isolates showed moderate activity for avicelase; however, Ganoderma neojaponicum showed the strongest activity. Moderate ligninase activity was only observed in Ganoderma neo-japonicum. In contrast, pectinase, amylase, protease, and cellulase were not present in Ganoderma. The results show that the degree of activity of the tested enzymes varied depending on the Ganoderma species tested.

• Korean Journal of Food Science and Technology
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• v.2 no.2
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• pp.38-42
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• 1970

The crude enzyme, tamylase, was produced by cultivating the Bacillus subtilis on wheat bran. It is composed of amylase and protease, and can be used as an additive material to the synthetic detergent, Suny which is manufactured by Ae-kyung Oil and Fat Co. Amylase activity of the enzyme as an additive material to the synthetic detergent; 1. is decreased by increasing the amount of detergent. But inhibitory rate under the practical used concentration of detergent is less than ten percents. 2. have optimal temperature at $ 40^{\circ}C$. 3. have optimal pH of substrate on pH $5{\sim}6.5$. 4. is inhibited by $Fe^{+++}$. When enzyme and detergent are mixed both as powder, the enzyme is good for storage. Proteolytic activity is good at the practical used concentration of the detergent, but it is inhibited by strong concentration.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.101-106
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• 2001

Alpha-amylase and glucoamylase activities were higher in koji with 40% water than that with 30 and 50% water, and A. oryzae exhibited very high alpha-amylase and glucoamylase activities compared to A. sojae and A. niger. Acidic, neutral and alkaline protease activities also showed higher activities in koji prepared with flour, Korean wheat powder and soybean powder with 40% water based on the weight of the sample. Alpha-amylase, acidic, neutral and alkaline protease activities of all the koji samples according to incubation periods increased until 3~4 days of incubation and maintained nearly the same level or slightly decreased after 5 days of incubation. The protease activities of A. oryzae and A. sojae showed nearly the same trend regardless of differences in substrate conditions and koji materials, but those of A. niger showed a lower activity than those of A. oryzae and A. sojae. These results suggest that the preparation of koji is possible with Korean wheat powder and soybean powder and A. sojae can be utilized as a new strain for fermented foods using soybean as the main materials to increase functional properties and produce products having a new taste and flavor.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.265-276
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• 2023

This study aimed to isolate and characterize fungi from freshwater environments in South Korea and evaluate their extracellular enzyme activities. Fungal strains were collected from various freshwater sources and identified using phylogenetic analysis. The isolated fungi included known aquatic hyphomycetes and previously unreported species. Extracellular enzyme, including those of protease, amylase, lipase, cellulase, laccase, and chitinase, activities were evaluated. Among the isolated strains, several showed high enzyme activity, suggesting their potential role in organic matter decomposition in freshwater ecosystems. This research expands our knowledge of the diversity and enzyme activities of the fungi in freshwater environments, contributing to our understanding of their ecological roles.