• Korean Journal of Microbiology
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• v.44 no.3
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• pp.264-269
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• 2008

To develop an amylolytic industrial yeast strain producing $\beta$-amylase, the BAMY gene encoding Achlya bisexualis $\beta$-amylase was constitutively expressed under the control of the alcohol dehydrogenase gene promoter (ADC1p) in an industrial strain of Saccharomyces cerevisiae. Yeast transformation was carried out by an integration system containing $\delta$-sequences as the recombination site. The integrative cassette devoid of bacterial DNA sequences was constructed that contains the BAMY gene and $\delta$-sequences. Industrial S. cerevisiae transformed with this integrative cassette secreted 45 kDa $\beta$-amylase into the culture medium. The $\beta$-amylase activity of the transformant was approximately 18.5-times higher than that of A. bisexualis. The multi-integrated BAMY genes in the transform ant were stable after 100 generations of growth in nonselective medium. Hydrolysis of soluble starch and various starches with the enzyme released maltose but not glucose or oligosaccharides.

• Applied Biological Chemistry
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• v.19 no.2
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• pp.82-92
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• 1976

The study was carried out to investigate the changes of the various chemical components and the microflora during the aging period of Korean navive Kochuzang. (Red pepper soybean paste) Korean native maeju loaves were separated into surface and inner parts. Three kinds of Korean native Kochuzang were prepared from surface part, inner part, and ordinary of maeju. The selection and the indentification of the high enzyme producing strains from the microflora and characteristics of their enzymes were studied. I. The changes of the various chemical components during the aging period of Kochuzang. 1) The changes of pH in the 3 kinds of Kochuzang displayed rapid decrease for the first 10 days after preparing and gradual curve of decrease until 60 days, but slight increase for the next 30 days. The pH of the surface part Kochuzang was lower than that of inner part or ordinary Kochuzang. 2) The total acid contents in the 3 kinds of Kochuzang showed gradual increase until the 60 days but it slowly reduced after this time. 3) The total nitrogen contents in the 3 kind of Kochuzang showed gradual inerease up to the 60 days, but slight decrease after this time. 4) The changes of trichloroacetic acid soluble nitrogen in the 3 kinds of Kochuzang showed a remarkable increase for the first 10 days, however gradual increase after this time. 5) The increase of amino nitrogen contents in the 3 kinds of Kochuzang seemed to be remarkable until the first 30 days, however to be less remarkable after this time. 6) The contents of reducing sugar in the 3 kinds of Kochuzang showed remarkable increase until the first 50 days and it slowly reduced after this time. II. The changes of microflora during the aging period of Kochuzang. 1) Aerobic, anaerobic bacteria and mold in the 3 kinds of Kochuzang were increased until the first 30 to 40 days, but they were reduced after this time. 2) No yeast in the three kinds of Kochuzang appeared until the first 20 days. Yeast were proved to grow, when the pH value was decreased below 5.4 after the 30 days. Yeasts in the surface part and ordinary Kochuzang were gradually increased and those in the inner part Kochuzang were decreased as aging. III. The selection and identification of high amylase and protease producing strains from the microflora during the aging period of Kochuzang. 1) The amylase and protease highly producing strains from microflora were identified as Bacillus subtilis-P, Bacillus subtilis-G, Bacillus licheniformis-K, Aspergillus oryzae-B. 2) Amylase activity of Aspergillus oryzae-B was highest among the strains and the strains in order of the higher activity to the lower one were Bacillus subtilis-P Bacillus licheniformis-K, Bacillus subtilis-G. Protease activities of Aspergillus oryzae-B and Bacillus subtilis-P were about the same and the strains in order of the higher activity to the lower one were Bacillus licheniformis-K, Bacillus subtilis-G. 3) Amylase activity was inhibited more than protease activity was with NaCl concentration. Amylase activity was inhibited by 45 to 65 percent and protease activity by 40 to 46 percent at the concentration of 15 percent NaCl, which was the average concentration of NaCl in Kochuzang.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.542-547
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• 2016

The thermal properties of ramie leaf ${\beta}$-amylase (RBA) were examined to develop a novel process for enzyme purification. The thermostability of RBA extract prepared from ramie leaf powder was examined at various temperatures. RBA activity decreased slightly, whereas other carbohydrate-active enzymes, such as $\small{D}$-enzyme, were rapidly inactivated during 30 min incubation at $60^{\circ}C$. When the heat-treated extract was incubated with various substrates, maltose was produced exclusively as the major product, whereas the untreated crude extract produced maltose and other maltooligosaccharides. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, fewer protein bands were observed for the heat-treated extract than the untreated extract, indicating that the thermostable RBA was partially purified and other thermolabile enzymes were eliminated. Thus, the treatment of the RBA extract at $60^{\circ}C$ for 30 min resulted in 5.4-fold purification with a recovery yield of 90%.

• Korean Journal of Plant Resources
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• v.27 no.6
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• pp.622-628
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• 2014

The aim of this work is to evaluate the potential of oriental melon (Cucumis melo L. var. makuwa Makino) seeds for the management of type 2 diabetes by controlling glucose absorption. The ${\alpha}$-glucosidase and ${\alpha}$-amylase inhibitory effects of the hexane extracts from oriental melon seeds were investigated. A bioassay-guided fractionation technique was used to elucidate the principal active components. The results show that the hexane extract from oriental melon seeds exhibited high inhibitory activities against ${\alpha}$-glucosidase and ${\alpha}$-amylase. The hexane extract was further fractionated into four sub-fractions. Among them, the sub-fraction F-1 exhibited the most potent anti-diabetic effect. The active components were isolated and identified by gas chromatography/mass spectroscopy (GC-MS). Free fatty acids showed significant hypoglycemic activity (p < 0.001) and fatty acid composition influenced enzyme inhibitory activities. These results suggest that oriental melon seeds could be used to prevent type 2 diabetes.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.295-302
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• 1989

This study was carried out as a preliminary test to investigate the improvement of soysauce and soybean paste for natural food. The soybean was treated on raw, soaked, roasted, and steamed condition and it was maked that rice koji was inoculated by Asp. oryzae, Asp. niger, Asp. awamori and on natural condition fermented. They were maked raw soybean-soypaste $(S_0)$, soaked soybean-soypaste $(S_1)$, roasted soybean-soypaste $(S_2)$, and steamed soybean-soypaste $(S_3)$ from soybean (60%), rice koji (30%) and salt (10%) respectively in order to investigate the changes of enzymes activity(amylase, protease, lipase and lipoxygenase activity) during fermentation of them. The results obtained were summarized as follows; Amylase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and $S_0>S_1>S_2>S_3$ in the soybean treatments. Protease activity was in the order of natural fermented microorganisms>Asp. niger>Asp. oryzae>Asp. awamori in the microorganisms, and $S_3>S_2>S_1>S_0$ in the soybean treatments. Lipase activity was a similar tendency in the microorganisms, but it was in the order of $S_0>S_1>S_3>S_2$ in the soybean treatments. Lipoxygenase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and $S_0>S_1>S_3>S_2$ in the treatments.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.365-369
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• 1986

The activity of glucoamylase and pullulanase, properties of glucoamylase and ethanol productivities of fusants were studied. Glucoamylase and pullulanase activity of fusants were higher than parents. The optimal pH and temperature of glucoamylase of fusants were very similar to the those produced by S. diastaticus. In alcohol fermentation. fermenting ability and fermentation rate of fusants were higher and faster than either of its parental strain. The maximum of alcohol yield in 15% of liquefied potato starch was 7.8% (v/v)

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.162-165
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• 2003

The enzyme activity and the micronutrient content of powdered raw meal (PRM) and powdered processed meal (PPM) were compared. PRM was made of freeze-dried cereals, fruits, and vegetables. PPM was made of the same materials as PRM, but with heat processing such as steaming, roasting and hot air drying. The activity of $\alpha$-amylase of PRM was higher than that of PPM. However there were no differences of the concentration of proximate components between PRM and PPM. The concentrations of vitamin A, C, folic acid, biotin, calcium, potassium, sodium and iron in PRM were higher than in PPM, but there were no differences in vitamins E, B$_1$, B$_2$, phosphorus and zinc. This research demonstrated that PRM retains greater nutritional value because there is higher enzyme activity and less loss of micronutrients during processing in PRM than in PPM.

• Korean journal of food and cookery science
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• v.9 no.4
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• pp.266-271
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• 1993

In order to investigate the traditional value of Ewhaju (traditional wine) and to establish the brewing condition, studies on of traditional background and field inquiry were carried out. Scientific evaluation and possibility of revealation of Ewhaju were searched by the experiments of microbial and enzymatic properties of brewed Ewhaju and Nuruk by traditional method. In flora of microorganisms in Nuruk of Ewhaju, Aspergillus oryzae and Hansenula sP. were isolated, and, showed a level of 1.2$\times$$10^6$ CHU/g, respectiveln but other microorganisms were not grown in diluted cultivation test. The a-and f-amylase activity of Nuruk were 30.74 and 34.4, respectively and their activities of two amylases were 19.28 and 18.8 at first stage of brewing, 21.21 and 19.80 at 100 day after brewing, and 20.25 and 19.90 at one year aged Ewhaju, respectively. The brewed Ewhaju could be remained with high quality long period without teat treatment or addition of preservatives, also, stored Ewhaju contains remarka-bly high activity of amylases which might contribute to digestion.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.219-227
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• 2023

This study was conducted to analyze the distribution and characteristics of fungal species in meju using the traditional method. Fungal distribution in meju was investigated using metagenomic and morphological analyses, based on which Aspergillus flavus/oryzae strains were identified as the dominant fungi in all meju samples, followed by Pichia, Rhizopus and Lichtheimia spp. As A. flavus/oryzae was dominant, we further evaluated the aflatoxin production ability and enzymatic activity of the isolates. Thin-layer chromatography and polymerase chain reaction revealed that the A. flavus/oryzae strains isolated from meju are non-aflatoxigenic fungi. Based on the analyses of amylase and protease activities, strains with high activities of amylase or protease were identified, which are proposed to be used as starters for meju fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.655-661
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• 2010

The nutraceutical role of fermented omija (Schizandra chinensis) beverage (FOB) was determined through the analysis of fibrinolytic and alcohol metabolizing activities, nitrite scavenging activity, and angiotensin converting enzyme and $\alpha$-glucosidase inhibitory effects. Firstly, FOB increased fibrinolytic activity in a dose-dependent manner and indicated angiotensin converting enzyme inhibitory activity of 94.8% at 20% FOB (0.6 mg/mL). In addition, the inhibitory activities of FOB on $\alpha$-amylase and $\alpha$-glucosidase were determined to be 100% at 100% FOB (3 mg/mL) and 49% at 60% FOB (1.8 mg/mL), respectively. Nitrite scavenging activity of FOB was about 96.1%, 72.3%, and 68.3% on pH 1.2, 3.0, and 6.0 at 100% FOB, respectively. To determine influence of FOB on alcohol metabolism, the generating activities of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) were measured. Facilitating rate of ADH activity was 70.3% at 50% FOB, but ALDH activity was not affected. These results revealed that FOB has a strong alcohol metabolizing activity, and fibrinolytic and nitrite scavenging activities and exhibits the angiotensin converting enzyme, $\alpha$-amylase, and $\alpha$-glucosidase inhibitory activities.