• Journal of Aquaculture
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• v.18 no.4
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• pp.245-251
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• 2005

This study was investigated the condition of their maximum activity to assay the enzymes of rotifer, Brachionus rotundiformis의 $\alpha$-amylase, total alkaline Protease, trypsin and TG-lipase activities of rotifer were higher and more sensitive in phosphate-NaOH buffer than Tris-HCl buffer. $\alpha$-amylase, trypsin and TG-lipase activities were appeared the maximum at pH 8.0, and total alkaline protease activity showed the maximum activity at pH 7.0. $\alpha$-amylase activity showed the highest activity at $40^{\circ}C$, and total alkaline protease and trypsin activities were assayed the highest at $55{\~}60^{\circ}C$. However, TG-lipase activity was appeared the highest at $25{\~}30^{\circ}C$. The optimum substrate concentration of enzyme activity of a-amylase, total alkaline protease, rypsin and TG-lipase were $3.5\%$ starch, $\0.6%$ azo-casein, $87.5{\mu}M$ BApNA and 81.2 mM olive oil, respectively. The optimum reaction time of enzyme activity of $\alpha$-amylase, total alkaline protease, trypsin and TG-lipase were increased up to 40, 60, 30 and 25 min., respectively. The data obtained in this study could be used for the digestive enzyme research of rotifer, B. rotundiformis.

• Microbiology and Biotechnology Letters
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• v.25 no.4
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• pp.379-385
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• 1997

Several protease-deficient mutants of Aspergillus niger have been isolated by halo-screening on skim milk plate after UV irradiation of conidiospores. The extracellular proteolytic activities of the mutant strains grown in an optimized medium varied from 3% to 85% of that of the parental strain. Especially, two mutant strains named as ANPD-129 and ANPD-153, which had 3% and 49% of acid protease activity of the parental strain, respectively, were further characterized both physiologically and genetically. The growth rates of the mutants, ANPD-129 and ANPD-153, were similar to that of the parental strain, unlike other protease-deficient mutants. The diploid formed between the two mutants restored protease activity to a similar level of that of the parental strain. This result revealed that ANPD-129 and ANPD-153 had mutations at different loci. Using master strains with marked chromosomes these loci were assigned to linkage groups. The mutation locus (prt129) in ANPD-129 was assigned to linkage group VI and the locus (prt153) in ANPD-153 to linkage group III.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.161-168
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• 1990

In order to investigate systematically characteristics of improved Kochujang in comparision with traditional Kochujang, changes of components in curing of two Kochujangs, enzyme activities of koji and Meju, and effects of salt and red pepper were measured. And it was found that the large differences of amino nitrogen and reducing sugar contents were appeared in the initial stage of the curing period, but the changes were parallel thereafter. The protease activity of koji was maximum in weak acidic pH and that of Meju was maximum in neutral pH. The optimum condition of substrate digestion was three hours at $60^{\circ}C$, and that was more effective than curing at room temperature. The activities of protease and saccharogenic amylase were decreased remarkably by adding salt and red pepper, Therefore, to decompose starch and protein effectively, the addition of salt and red pepper after substrate digestion was more favorable.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.251-256
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• 2008

Eoyukjang is a traditional sauce-type of Korean food that is similar to a soybean sauce made from fermented soybeans, and it is produced from a fermented mixture of sea foods, meats, and meju (soybean paste). This study examined periodical changes in the enzymatic activities of ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, protease, lipase, and lipoxygenase within the culture broth and solids of eoyukjang during 1 year of fermentation. The eoyukjang solids had 234-532% higher protein content than the culture broth. The specific activities of ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, and protease increased in both the culture broth and solids. Particularly, in the culture broth, ${\alpha}$-amylase, esterase, ${\beta}$-glucosidase, and protease activities rapidly increased (3- to 8-fold) until 10 months of fermentation, and then drastically decreased. However, the activities of lipase and lipoxygenase in both the culture broth and solids were less than 0.05 unit/mg of protein, respectively, throughout fermentation; thus, their activity levels were low and changed little over the 12 months. Overall, while the solids had higher protein content than the culture broth, the broth had greater enzyme activity levels during eoyukjang preparation.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.65-74
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• 1996

Treatment of regenerating amphibian limbs with retinoic acid (RA) is known to induce paftern duplication, which is closely related to the extent of dedifferentiation. In the present study, the activities of trypsin- and chymotrypsin-like proteases are examined to delineate a possible role in the process of dedifferentiation in the regenerating limbs of urodeles, the Korean salamander (Hynobius leechii) and the Mexican axolod (Ambystoma mexicanum). Specifically, we were interested to know if there is any correlation between trypsin- and chymotrypsin-like protease activities and the state of dedifferentiation which is augmented by RA treatment. We were also interested in expoloring if there is any species-specific difference in the profile of enzyme activities during limb regeneration. The results showed that the activities of these two enzymes reached a peak level at dedifferentiation stage, and RA treatment caused elevation of their activities, especially in the case of trypsin-like protease. The increase of trypsin-like protease activity after RA treatment was pronounced in the Korean salamander, which might reflect a species-specific responsiveness to RA. The present results imply that trypsin and chymotrypsin or similar proteases may play an active role in the process of dedifferentiation in regenerating limbs, and that trypsin or trypsin-like eryrymes might be involved in the RA-evoked enhancement of dedifferentiation which precedes overt pattern duplication.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.59-64
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• 1994

The production and the characteristics of protease produced by Bacillus sp. SH-8 and Bacillus sp. SH-8M were investigated under the different pH conditions. Bacillus sp. SH-8 and Bacillus sp. SH-8M showed the maximum activity of protease at 60 hours(70 units/ml) AND 96 houre(50 units/ml) cultivation, respectively, under the alkaline condition(pH 10.2). However, Bacillus sp. SH-8M exhibited the maximum activities in 8 days cultivation at pH 6.9 and in 6 days cultivation at pH 7.7 Bacillus sp. SH-8M showed the protease activity at the pH change from alkaline to neutral condition, whereas Bacillus sp. SH-8 did not. In addition. all the enzymatic characteristics of protease produced by Bacillus sp. SH-8 and Bacillus sp. SH-8M were similar with the regardless of different pH conditions.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.519-526
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• 2008

To improve the quality of traditional kochujang, strains with high protease and amylase activity were isolated and identified from Sunchang traditional kochujang. Twenty-three strains strongly producing protease and 16 strains strongly producing $\alpha$- and $\beta$-amylase were isolated by using 1% isolated soy protein agar medium and 2% starch agar medium, respectively. Protease activities of the IA7, I5, and IA2 strain were 22.5, 21.2, and 20.6 unit/mL, respectively, and were higher than those of the other strains. Stains with high $\alpha$-amylase activity included K9 (967.8 unit/mL), K14 (828.3 unit/mL), K13 (662.5 unit/mL), K8 (601.5 unit/mL), and K11 (405.9 unit/mL). The $\beta$-amylase activity of the K11 strain was the highest, 34.3 unit/mL, among the isolated strains. Based on morphological, physiological properties, and API 50CHB-kit test for assimilation of 49 carbohydrates, 8 strains selected according to protease, $\alpha$-amylase, and $\beta$-amylase activities were tentatively identified as Bacillus megaterium (IA2), Bacillus subtilis (IA7, 15), Bacillus amyloliquefaciens (K8, K9, K11, and K13), and Bacillus stearothermophillus (K14). The IA7, 15, and K11 strains were finally identified as B. subtilis (99% ID) based on 16S rDNA sequencing.

• Parasites, Hosts and Diseases
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• v.30 no.3
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• pp.227-230
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• 1992

Spirometra mansoni plerocercoid (sparganum) was incubated in saline at $4^{\circ}C{\;}or{\;}37^{\circ}C$ up to 100 hours. Protein contests in the excretory$.$secretory product (ESP) were rather constant (mean 7.7 mg of protein/gram of sparganum) in the preparations. Reducing SDS-PAGE of ESP showed similar protein subunit compositions with those in crude extract. Antigenic 36 and 31 kDa Proteins were major bands in ESP. ESP exhibited specific activities of protease(2.9~5.3 units/mg) at pH 6.0 and pH 7.5. Presence of protease activity in ESP may be a supporting evidence that hitherto known cysteiRe protease of sparganum is possibly secreted.

• Korean Journal of Microbiology
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• v.35 no.4
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• pp.296-301
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• 1999

A Bacillus strain from Korean soil was isolated and identified to be Bacillus licheniformis B1 through various biochemical tests, VITEK, and MIDI system analysis. The strain produced extracellular amylase and protease. Whether or not the strain can perform Chungkookjang fermentation with autoclaved soybean and Kanjang fermentation was determined in this study. In Chungkookjang fermentation, browining materials of strong anti-oxidant increased 8-fold, and 2-fold in Kanjang, compared with initiation material for fermentation. Maximal protease activity in Chungkookjang was observed one day after inoculation. Protease activities in Kanjang decreased to the half, and then maintained constant values during fermentation, probably due to the inhibitory effect of salt on protease activities. High molecular mass of nucleic acids was identified in Chungkookjang and Kanjang. Since the nucleic acids were not observed in autoclaved soybean, they seem to be originated from B. licheniformis B1. This study demonstrated successive fermentation of Chungkookjang and Kanjang by B. licheniformis B1 isolated from nature, and suggested possible development of food rich in browing and nucleic acids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.228-233
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• 1995

To make Natto, tradiational Japanese food fermented by Bacillus natto, more acceptable to Koreans, garlic(2%) and/or red pepper oleoresin(0.2%) were mixed with Natto. Through out the fermentation period, the changes in enzyme activities and sensory evaluation were compared with those of conventional Natto. Nattokinase activities were detected from 12 hour fermentation in all samples. After that period, steady increased in Nattokinase activity was observed. The activity of nattokinase decreased slightly when garlic and/or red pepper oleoresin was added. Changes in ${\gamma}-glutamyl$ transpeptidase(${\gamma}-GTP$) was not significant among samples and the similar tendency was observed in nattokinase activity. With addition of garlic, production of protease reached maximum after 8 hour of fermentation whereas it took 16 hour when red pepper oleoresin was added. However, after 24 hour of fermentation, any significant differences in protease activity were not observed. Sensory evaluation indicated that the tastes of Natto with either garlic and red pepper oleoresin or red pepper oleoresin only were much more acceptable than conventional Natto or one with garlic only.