• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.829-835
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• 2004

A fibrinolytic enzyme has been found in several bacteria isolated from fermented food. This study was carried out to investigate the purification and characteristics of the fibrinolytic enzyme produced by Bacillus subtilis KCK-7 originated from Chungkookjang. The fibrinolytic enzyme was purified to homogeneity from the culture supernatant using ammonium sulfate fractionation and chromatographies on DEAE-cellulose and on Sephadex G-100. The final specific activity of the purified enzyme increased 11.0-fold, and the protein amount in the purified enzyme was about 16% of that in the culture supernatant. The molecular weight of the purified enzyme was estimated to be about 45,000 by SDS-PAGE. The optimum pH and temperature for the enzyme activity were pH 7.0 and $60^{\circ}C$, respectively. The enzyme activity was relatively stable up to $60^{\circ}C$ over the pH range of 7.0-10.0. The fibrinolytic enzyme activity increased by $Ca^{2+}$ and $Cu^{2+}$, whereas it was inhibited by $Hg^{2+}$ and $Ba^{2+}$. In addition, it was severely inhibited by PMSF and DFT. It is suggested that the purified enzyme was a serine protease for the fibrinolysis. The purified enzyme could completely hydrolyze fibrin in vitro within 8 h. Hence, it is suggested that the purified enzyme can be put into practice as an effective thrombolytic agent.

• Food Science and Preservation
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• v.21 no.1
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• pp.121-128
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• 2014

This study was conducted in order to investigate the change of isoflavone composition (glycoside and bio-active aglycone), and to evaluate the quality characteristics of Cheonggukjang, which was prepared by different bacillus strains. After the 48-hour fermentation, the contents of daidzein, genistein, and glycitein in the Bacillus subtilis HJ18-3 have significantly increased up to approximately $89.06{\pm}3.59$, $10.36{\pm}0.28$, and $101.37{\pm}3.67ug/g$, respectively. The contents of daidzein, genistein, and glycitein in the Bacillus subtilis KACC 15935 were $38.88{\pm}5.39$, $12.58{\pm}2.14$, and $80.13{\pm}0.71ug/g$, respectively. The original content of daidzein was 3.96 ug/g, while genistein and glycitein were not measured. However, the contents of daidzen and genistein in HJ18-3 and in KACC 15935 were decreased. The ${\alpha}$-Amylase and cellulase activities of Chungkookjang in HJ18-3 were higher than in the KACC 15935. The contents of Chungkookjang in HJ18-3 were $29.70{\pm}11.66$ and $4861.3{\pm}388.07unit/g$, respectively. The amino type nitrogen contents and ammonia type nitrogen contents of Chungkookjang in KACC 15935 were higher than in the HJ18-3. These results suggested that it could be used to increase the bioactivity via fermentation with the Bacillus subtilis possessing a ${\beta}$-glucosidase activity with a view towards the development of functional foods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.7
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• pp.826-833
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• 2008

The effects of porphyran-chungkookjang on cytotoxicity of human normal cell line (BJ) and human cancer cell lines (AGS and HT-29) were examined. Porphyran, which was prepared from laver (Porphyra yezoensis), decreased the viability of the cancer cells, however, it did not affect the viability of normal cells. Porphyranchungkookjang was prepared by the addition of 5% (w/w) porphyran into chungkookjang which was fermented by starter, Bacillus subtilis DJI. The cytotoxicity effects of the chungkookjang and porphyran-chungkookjang were evaluated with MTT assay. The methanol and the water extract of porphyran-chungkookjang at 1.0 mg/mL showed $23{\sim}38%$ decreases in proliferation of cancer cells (AGS and HT-29). However, the methanol and the water extracts of porphyran-chungkookjang did not inhibit the growth of normal cell. Moreover, the methanol extract of porphryan-chungkookjang at 1.0 mg/mL showed $1.2{\sim}1.5$ fold higher anticancer effects than that of the chungkookjang.

• Journal of Environmental Science International
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• v.22 no.6
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• pp.723-732
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• 2013

This study was carried out to investigate changes of protease and amylase activities and nitrogen content in Chungkookjang prepared by Bacillus subtilis S8 and different soybean. Amino-type nitrogen and ammonia-type nitrogen contents increased with an increase in fermentation time and was the highest in black soybean Chungkookjang. The number of viable cells increased up to 24 h of fermentation at all temperatures tested; especially, their levels were the highest at $40^{\circ}C$. Protease activity was the highest in black soybean Chungkookjang. ${\alpha}$-amylase activity increased significantly up to 6 h of fermentation at $30^{\circ}C$ and $40^{\circ}C$ and then maintained constantly. It also increased up to 30-36 h of fermentation at $45^{\circ}C$ and then decreased. ${\beta}$-amylase activity was the highest in black soybean Chungkookjang at $35^{\circ}C$ and $40^{\circ}C$ and in yellow soybean Chungkookjang at $45^{\circ}C$. Production pattern of reducing sugar was similar to that of ${\beta}$-amylase. Amino-type nitrogen, viable cell number and reducing sugar content and ${\beta}$-amylase activity was the highest in Chungkookjang fermented at $40^{\circ}C$. Considering amino-type and ammonia-type nitrogen contents, Chungkookjang fermentation using yellow soybean was favorable. However, the fermentation using black soybean was favorable, considering protease and amylase activities and reducing sugar content.

• Journal of Applied Biological Chemistry
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• v.52 no.3
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• pp.151-156
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• 2009

As part of an investigation to identify microorganisms that are biotechnologically interesting for industrial application, we isolated a bacterial strain from Chungkookjang that produces extracellular neutral lipase. In addition, the crude enzyme was characterized. This isolated strain, designated as JKA-3 was identified as Bacillus subtilis JKA-3 based on morphological, physiological and biochemical characteristics, as well as phylogenetic analysis using 16S rRNA gene sequence. The cells were rod-shaped and $0.6-0.8{\times}2.0-2.3\;{\mu}m$ in size. Optimal growth conditions were $35-40^{\circ}C$ and pH 6.0-8.0. The isolate was able to grow in up to 0-10.0% (w/v) NaCl. Optimal activity conditions of the crude lipase fraction of B. subtilis JKA-3 were pH of 7.0 at $35^{\circ}C$. This enzyme was stable in the pH ranging 6.0-8.0.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.677-684
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• 2012

A bacterium strain GS-2 isolated from the Korean traditional seasoning food, Chungkookjang and was determined to produce large amounts of ${\gamma}$-PGA with high productivity when provided with simple nutrients (L-glutamic acid 2.0%, glucose 1.0%, $NH_4Cl$ 0.5%, $KH_2PO_4$ 0.05%, $MgSO_4{\cdot}7H_2O$ 0.01%, pH 7.0). In this study, the culture medium for this strain was optimized for the production of ${\gamma}$-PGA. The Bacillus subtilis GS-2 required supplementation with L-glutamic acid and other nutrients for maximal production of ${\gamma}$-PGA. The optimal culture conditions for ${\gamma}$-PGA production were a 48 hr culture time, a temperature of $33^{\circ}C$ and initial pH of 6.5 by rotary shaking (220 rpm). A maximum ${\gamma}$-PGA production of 31.0 $g/{\ell}$ was obtained with L-glutamic acid (30 $g/{\ell}$), sucrose (the main carbon source, 30 $g/{\ell}$), $NH_4Cl$ (the main nitrogen source, 2.5 $g/{\ell}$), $KH_2PO_4$ (1.5 $g/{\ell}$) and $MgSO_4{\cdot}7H_2O$ (0.15 $g/{\ell}$) in the culture medium.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1436-1439
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• 2010

Many studies have clarified that poly(${\gamma}$-glutamic acid) (PGA) increases the solubility of $Ca^{2+}$, suggesting that PGA enhances calcium absorption in the small intestine. However, there has been no report on the specific interaction between PGA and $Ca^{2+}$ in water. We studied the aqueous solution properties of PGA calcium salt (PGA-Ca complex). The chelating ability and binding strength of PGA for $Ca^{2+}$ were evaluated. The PGA-Ca complex was soluble in water, in contrast to the insolubility of poly(acrylic acid) (PAA) calcium salt, and the chelating ability of PGA for $Ca^{2+}$ was almost the same as that of PAA. The globular conformation of the PGA-Ca complex in water was estimated by SEC and viscosity measurements. The chelation ability of PGA for $Ca^{2+}$ was examined by $^1H$ NMR. The present study showing the characteristics of the PGA-Ca complex will provide useful information about the calcium absorption by PGA in vivo.

• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.39-47
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• 2005

Using the bacteria isolated from Chungkookjang, Bacillus sublilis MG410 which is excellent in fibrinolytic enzyme activity was isolated. In increase the high production of fibrinolytic enzyme from Bacillus sublilis MG410, the effect of various carbon sources, nitrogen sources, inorganic sources, the initial pH of medium were investigated. The most effective carbon and nitrogen sources were founded cellobiose 0.5%(w/v) and soybean meal 2%(w/v) respectively. None of inorganic sources examined had any detectable stimulating effect on fibrinolytic enzyme production except Na₂HPO₄·12H₂O. The initial optimum pH for fibrinolytic enzyme production ranged from 5∼6 and agitation speed was effect at 150rpm. In jar fermentor experiments under optimal culture conditions, the activity of fibrinolytic enzyme reached about 5.050 unit after 48hours.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.49-55
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• 2011

Thirty Streptomyces sp. and 200 Bacillus sp. isolated from Korean soils and traditional foods were screened for their abilities to inhibit ${\alpha}$-glucosidase and produce 1-deoxynojirimycin (DNJ). This screening identified a Bacillus sp. bacterium that strongly inhibited ${\alpha}$-glucosidase and produced high levels of DNJ from Chungkookjang, a Korean traditional food. The bacterium was characterized in terms of its biochemical and molecular biological properties such as sugar utilization, cellular quinone composition, cell wall fatty acid composition, and 16S rDNA sequence. In addition, scanning electron microscopy was used to visualize the morphology of the bacterium. These analyses identified the bacterium as B. subtilis, a bacterium with Generally Recognized as Safe (GRAS) status. The selected strain was named B. subtilis MORI.

• Journal of Microbiology and Biotechnology
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• v.15 no.4
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• pp.855-858
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• 2005

The bioavailability of Ca is currently one of the most important topics in nutrition research and is correlated with gastrointestinal solubility. Thus, to increase the solubility of calcium, this study was undertaken to examine the effect of $\gamma$-PGA on intestinal Ca solubility. The calcium solubility increased when the amount of $\gamma$-PGA was increased, due to the inhibition of the formation of an insoluble Ca complex with phosphate. Therefore, when $\gamma$-PGA-500 (avg. MW 5,000 kDa) was added at 0.5 mg/ml, $75\%$ of the total Ca was soluble. The amount of soluble Ca uptake in the small intestine was investigated using Balb/c mice as an animal model system. The soluble Ca uptake in the mice orally administered with $\gamma$-PGA-500 (avg. MW 5,000 kDa) was significantly higher than that in the $\gamma$-PGA-l00 (avg. MW 1,000 kDa)-administered mice (P<0.05). Accordingly, these results strongly support the notion that the molecular size of $\gamma$-PGA is correlated with Ca solubility. The effects of other factors, such as casein phosphopeptide and vitamin D, on intestinal Ca absorption have also previously been investigated. Therefore, it is hoped that the present observations will help clarify the role of $\gamma$-PGA in Ca solubility and its industrial application as an additive.