• Korean Journal of Microbiology
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• v.31 no.2
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• pp.157-165
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• 1993

A 1, 4-.betha.-D-xylanase, designated as xylanase II, was purified from the culture filtrate of Trichoderma koningii ATCC 251131 by column chromatography on Sephadex G-75, SP-Sephadex C-50, DEAE-Sephadex A-50 and Sephadex G-50 with an overall yield of 6.97%. It has a molecular weight of 21.000 and an isoelectric point of 9.4. The enzyme activity is optimal at pH 5.0 and at a temperature of 50.deg.C. Xylanase II is stable up to 50.deg.C, while 40 and 90% of its activity are lost after the incubation for 30 and 60 min at 60.deg.C. The enzyme degrades xylan with relatively high activity, as well as carboxymethylcellulose and Avicel. Its $K_{m}$ values for oat-spelt xylan, larchwood xylan and Avicel are 7.48, 1.98 and 13.33 mg/ml, respectively. The hydrolysis products of oat-spelt xylan by xylanase II are xylose, xylobiose, xylotriose and arabinoxylotriose, while the reaction products of larchwood xylan are xylose, xylobiose, xylotriose and small amount of higher oligomers. The action paterns of the enzyme demonstrate that xylanase II is endo-enzyme.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1544-1553
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• 2013

Despite the importance of acetate kinase in the metabolism of bacteria, limited structural studies have been carried out on this enzyme. In this study, a three-dimensional structure of the Escherichia coli acetate kinase was constructed by use of molecular modeling methods. In the next stage, by considering the structure of the catalytic intermediate, trifluoroethanol (TFE) and trifluoroethyl butyrate were proposed as potential inhibitors of the enzyme. The putative binding mode of these compounds was studied with the use of a docking program, which revealed that they can fit well into the enzyme. To study the role of these potential enzyme inhibitors in the metabolic pathway of E. coli, their effects on the growth of this bacterium were studied. The results showed that growth was considerably reduced in the presence of these inhibitors. Changes in the profile of the metabolic products were studied by proton nuclear magnetic resonance spectroscopy. Remarkable changes were observed in the quantity of acetate, but other products were less altered. In this study, inhibition of growth by the two inhibitors as reflected by a change in the metabolism of E. coli suggests the potential use of these compounds (particularly TFE) as bacteriostatic agents.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.80-88
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• 2018

This study was conducted to develop easily chewable Korean rice cake (Garaedduk) for the elderly while maintaining its original form and flavor. We developed two types of easy-to-chew Garaedduk products by adding starch-degrading enzyme or trehalose, respectively. Characteristics of Garaedduk products were investigated and comparative analysis was carried out between control and experimental groups. The water content of control and enzyme-added Garaedduk was 43.55% and 44.11%, respectively, which was significantly higher than trehalose-added Garaedduk (40.30%) as free water content was reduced by the formation of hydrogen bonds between trehalose and water molecules. Due to the browning of reducing sugar produced by the decomposition of rice starch, Hunter b-value of enzyme-added Garaedduk was significantly higher compared to others. Hardness, adhesiveness, gumminess, and chewiness of experimental groups were lower than the control group. Consumer test scores showed significant differences with respect to overall liking, chewiness, and swallowing between control and experimental groups. Elderly preferred experimental Garaedduks over control and the experimental groups were evaluated to be softer, easily chewable, and swallowable.

• Journal of Ginseng Research
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• v.36 no.3
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• pp.291-297
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• 2012

Ginsenoside (ginseng saponin), the principal component of ginseng, is responsible for the pharmacological and biological activities of ginseng. We isolated lactic acid bacteria from Kimchi using esculin agar, to produce ${\beta}$-glucosidase. We focused on the bio-transformation of ginsenoside. Phylogenetic analysis was performed by comparing the 16S rRNA sequences. We identified the strain as Lactobacillus (strain 6105). In order to determine the optimal conditions for enzyme activity, the crude enzyme was incubated with 1 mM ginsenoside Rb1 to catalyse the reaction. A carbon substrate, such as cellobiose, lactose, and sucrose, resulted in the highest yields of ${\beta}$-glucosidase activity. Biotransformations of ginsenoside Rb1 were analyzed using TLC and HPLC. Our results confirmed that the microbial enzyme of strain 6105 significantly transformed ginsenoside as follows: Rb1${\rightarrow}$gypenoside XVII, Rd${\rightarrow}$F2 into compound K. Our results indicate that this is the best possible way to obtain specific ginsenosides using microbial enzymes from 6105 culture.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.74-78
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• 2008

Liquiritin in licorice (Glycyrrhiza uralensis Fisch) extract was treated with three different plant crude enzymes (Prunus dulcis enzyme; PDE, P. armeniaca enzyme; PAE and P. persica enzyme; PPE) for biotransformation. The resulting product of liquiritin was analyzed by TLC and HPLC. The ${\beta}glucosidase$ activities of crude enzymes were 259.6 U/g (PDE), 407.6 U/g (PAE) and 445.8 U/g (PPE), respectively. The liquiritin was converted to liquiritigenin after 12 hours of incubation with the crude enzymes. Liquiritigenin content reached its maximum level after the treatment with PPE at $37^{\circ}C$.

• Journal of Food Hygiene and Safety
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• v.37 no.1
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• pp.15-20
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• 2022

The purpose of this study was to compare the conventional culture method, enzyme immune method and the PCR method using species-specific primer in the analysis on the Salmonella spp. found in domestically distributed pet foods. For the study, Salmonella spp. were detected from 175 samples. From the conventional culture method and the PCR method, two samples (jerky and corn gluten) were determined as positive. Also, from the enzyme immune method, one sample (corn gluten) was test-positive. The study revealed that application of the PCR method with species-specific primer allows better distinguishment between the species of the strain collected from the samples than the conventional culture method and/or the enzyme immune method.

• Biomolecules & Therapeutics
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• v.2 no.2
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• pp.120-125
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• 1994

We obtained the total protein antibodies of Saccharomyces cerevisiae KCTC 1720 and Escherichia coli K-12 from the rabbit and the guinea pig to determine the host-derived proteins which may be remained in biotechnological products. The protein concentration of rabbit antibodies was 4.05 mg/mι in the case of yeast, 7.14 mg/mι in the case of E. coli and that of guinea pig antibodies was 1.90 mg/mι in the case of yeast, 7.17 mg/mι in the case of E. coli, respectively. To determine remained host-derived proteins in biotechnological products which produced by the hosts, S. cerevisiae or E. coli, we used a sandwich enzyme linked immunosorbent assay method in 96 well microplate. When the method applied to determine the remained host-derived proteins in commercial biotechnological products, it detected less than 3.5 ng/vial in human growth hormone, less than 1 ng/vial in hepatitis B vaccine and interferon-${\gamma}$ and 2~23 ng/vial in interferon-$\alpha$. The method can be used to determine the remained host-derived protein in biotechnological products.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.202.4-203
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• 2003

The present study was carried out to clarify whether isoflavonoids isolated from Belamcandae Rhizoma (Iridaceae) inhibit inflammation and angiogenesis by the experimental methods in vitro and in vivo. Among the isolated isoflavonoids, such as irigenin, irisflorentine, and iristectorene B inhibited nitric oxide (NO) production, as measured by nitrite formation at 3-30 ${\mu}M$. Also these compounds reduced cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) enzyme expression in a concentration dependent manner, when measured by western blotting, at 3-30 ${\mu}M$. Irigenin, irisflorentine and iristectoren B decreased angiogenesis of chick embryos in the chorioallantoic membrane assay. These compounds also reduced the proliferation of calf pulmonary arterial endothelial (CPAE) cells and found to possess relatively weak gelatinase/collagenase inhibitory activity in vitro. These compounds, when administered subcataneously at the dose of 30mg/kg for 20 days to mice implanted with murine Lewis lung carcinoma (LLC), caused a significant inhibition of tumor volume. Therefore, antiangiogenic activities of isoflavonoids from Belamcandae Rhizoma might be due to antiproliferative activities under inhibition the induction of COX-2 and iNOS enzyme.

• Applied Biological Chemistry
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• v.33 no.1
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• pp.79-86
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• 1990

Cyclodextrin hydrolase from Bacillus stearothermophilus KFCC 21203 was purified and the properties of the purified enzyme were investigated. The enzyme was purified 15 folds with 77 % recovery by ammonium sulfate fractionation, DEAE-cellulose chromatography, and Ultro AcA 34 gel filtration. The specific activity and the molecular weight of the enzyme were 1.30 units/mg protein and about 29,500, respectively, The maximum activity of the enzyme was shown at $55^{\circ}C$ and pH 5.5. However, stable temperature and pH were $40^{\circ}C$ and $5.0{\sim}8.0$, respectively. The Km value for ${\gamma}-cyclodextrin$ was $3.78{\times}10^{-3}$ M. The degradation activity of the enzyme was selectively high for ${\gamma}-cyclodextrin$, and very low for ${\beta}-cyclodextrin$, but not for ${\alpha}-cyclodextrin$. The decomposed products of ${\gamma}-cyclodextrin$ were mainly glucose and maltose, and a little mlatotriose. The activity of the enzyme was very high for amylose, potato starch, corn starch, amylopectin and maltooligomer, and relatively high for glycogen and dextrin. The decomposed products of them were mainly glucose and maltose.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1434-1439
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• 2001

Eighty crossbred pigs (Large White x Landrace) weighing 9.9 kg were assigned on the basis of sex, weight and Jitter to one of five dietary treatments in a factorial $(5\;treatments\;{\times}2\;sexes)$ arrangement to compare the nutritive value of hulled and dehulled peas fed with or without enzyme (0.25% Allzyme PF and 0.5% Biogal-S). A barley and soybean meal diet served as a control. Eight castrates and eight gilts were fed each diet. Digestibility coefficients for dry matter, crude protein and energy were higher for diets containing dehulled peas than hulled peas. In addition, enzyme supplementation modestly increased the digestibility of all three nutrients. Over the entire experimental period (9.9 to 103.3 kg), there were no performance differences (p>0.05) between pigs fed soybean meal based diets or diets based on any of the pea products. In addition, there were no differences in performance between pigs fed diets containing hulled or dehulled peas or between pigs fed diets with or without dietary enzyme. Castrates gained weight significantly faster, consumed more feed but had a poorer feed conversion than gilts (p<0.05). There were no differences in carcass traits between pigs fed diets based on soybean meal or any of the pea products. Carcass traits were similar for pigs fed hulled or dehulled peas while enzyme supplementation also had no effect on carcass data. Castrate pigs had a lower carcass value index, estimated lean yield and loin lean depth (p<0.05). Loin fat depth was greater for castrates than gilts (p<0.05). The overall results of this experiment provide little support for the need for enzyme supplementation of pea based diets fed to swine. In addition, dehulling did not appreciably improve the nutritive value of peas. Therefore, since the process adds to the cost of the raw product, its use is unlikely to be economical.