• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.12
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• pp.1694-1699
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• 2011

The quality characteristics and physiological effects of chunggukjang fermented naturally (NF-c), with Bacillus subtilis-SKm (BS-c), with Bacillus subtilis HJ18-4 (BH-c), and with Bacillus subtilis KCCM 42923 (BK-c) were investigated. The characteristics of fermentation were determined by protease, ${\alpha}$-amylase and ${\gamma}$-GTP activities, and additionally the amounts of amino-type and ammonia-type nitrogens. BS-c showed the highest protease, ${\alpha}$-amylase, and ${\gamma}$-GTP activities, and also amino-type nitrogen content among the four types of chunggukjang. The ammonia-type nitrogen content in BS-c was similar to that of BK-c and NF-c. BH-c showed the lowest enzyme activities and amino-type and ammonia-type nitrogen content. BS-c, BH-c, BK-c, and NF-c showed a similar overall acceptability during sensory evaluation. BS-c also showed the strongest DPPH free radical scavenging and anti-proliferative activities in HT-29 human colon carcinoma cells. These results suggested that B. subtilis-SKm was suitable to be used as a starter to enhance the quality and effects of chunggukjang.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.189-196
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• 1992

A $\alpha$-l, 4-D-glucan maltohydrolase $(\beta$-amylase), secreted by the mesophilic aerobic bacterium Bacillus polymyxa No.26, was purified and characterized. The enzyme production was increased after a logarithmic phase of bacterial growth and paralleled with the onset of bacterial sporulation. By applying anion exchange chromatography and gel filtration the enzyme was purified 16.7-fold and had a specific activity of 285.7 units/mg. Two enzyme activities were eluted on a column of DEAE-Sephadex chromatography, and they were designated as E-I for a major enzyme peak and E-II for a minor peak. Of them, E-I enzyme peak was further purified by using gel chromatography. The molecular mass of this enzyme was determined to be 64, 000 daltons and consisted of a single subunit, showing an isoelectric point of 8.9. The enzyme was able to attack specifically the $\alpha$-l, 4-glycosidic linkages in soluble starch and caused its complete hydrolysis to maltose and $\beta$-limited dextrin. This amylolytic enzyme displayed a temperature optimum at $45^\circ{C}$ and a pH optimum at 7.0. The amino acid composition of the purified enzyme was quite similar to the other bacterial $\beta$-amylases reported. Surprisingly, the purified enzyme from this aerobe only exhibited hydrolytic activity on soluble starch, not on starch granules. The degradation of from starch by $\beta$-amylase was greatly stimulated by pullulanase addition. These results differentiated from other $\beta$-amylases reported. Based on a previous result that showed the enzyme system involves in effective degradation of raw starch granules, this result strongly suggested that the purified enzyme (E-I) can be a synergistic part of starch granule-digestion and E-II plays a crucial role in digestion of starch granules.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1164-1173
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• 2006

Cellulase from Aspergillus niger, (${\alpha}$-amylase from Bacillus sp. and protease from Bacillus globigii were used as enzyme sources in this study to examine how their respective substrates protect them in two kinds of simulated gastrointestinal tract digesting processes. Avian total digest tract simulation test showed that filter paper, Avicel and cellulose resulted in 7.7, 6.4 and 7.4 times more activity than of unprotected cellulose, respectively. Protease with addition of casein, gelatin or soybean protein showed no significant protection response. Starch protected amylase to be 2.5 times activity of the unprotected one. Monogastric animal total tract digestion simulation test showed that filter paper, Avicel and cellulose resulted in 5.9, 9.0 and 8.8 times activity of unprotected cellulase, respectively. Casein, gelatin and soybean protein resulted in 1.2, 1.3 and 2.0 times activity of unprotected protease, respectively. Starch did not protect amylase activity in monogastric animal total tract simulation. Protection of mixed enzymes by substrates in two animal total tract simulation tests showed that filter paper in combination with soybean protein resulted in 1.5 times activity of unprotected cellulose, but all substrates tested showed no significant protection effect to protease. Soybean protein and starch added at the same time protected the amylase activity to be two times of the unprotected one. Test of non-purified substrate protection in two animal total digest tract simulation showed that cellulase activity increased as BSA (bovine serum albumin) concentration increased, with the highest activity to be 1.3 times of unprotected enzyme. However, BSA showed no significant protection effect to protease. Amylase activity increased to 1.5 times as BSA added more than 1.5% (w/v). Cellulase activity increased to 1.5 times as soybean hull was added higher than 1.5%. Amylase had a significant protection response only when soybean hull added up to 2%. Protease activity was not protected by soybean hull to any significant extent.

• BMB Reports
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• v.40 no.3
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• pp.315-324
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• 2007

The novel $\alpha$-amylase purified from locally isolated strain, Bacillus sp. KR-8104, (KRA) (Enzyme Microb Technol; 2005; 36: 666-671) is active in a wide range of pH. The enzyme maximum activity is at pH 4.0 and it retains 90% of activity at pH 3.5. The irreversible thermoinactivation patterns of KRA and the enzyme activity are not changed in the presence and absence of $Ca^{2+}$ and EDTA. Therefore, KRA acts as a $Ca^{2+}$-independent enzyme. Based on circular dichroism (CD) data from thermal unfolding of the enzyme recorded at 222 nm, addition of $Ca^{2+}$ and EDTA similar to its irreversible thermoinactivation, does not influence the thermal denaturation of the enzyme and its Tm. The amino acid sequence of KRA was obtained from the nucleotide sequencing of PCR products of encoding gene. The deduced amino acid sequence of the enzyme revealed a very high sequence homology to Bacillus amyloliquefaciens (BAA) (85% identity, 90% similarity) and Bacillus licheniformis $\alpha$-amylases (BLA) (81% identity, 88% similarity). To elucidate and understand these characteristics of the $\alpha$-amylase, a model of 3D structure of KRA was constructed using the crystal structure of the mutant of BLA as the platform and refined with a molecular dynamics (MD) simulation program. Interestingly enough, there is only one amino acid substitution for KRA in comparison with BLA and BAA in the region involved in the calcium-binding sites. On the other hand, there are many amino acid differences between BLA and KRA at the interface of A and B domains and around the metal triad and active site area. These alterations could have a role in stabilizing the native structure of the loop in the active site cleft and maintenance and stabilization of the putative metal triad-binding site. The amino acid differences at the active site cleft and around the catalytic residues might affect their pKa values and consequently shift its pH profile. In addition, the intrinsic fluorescence intensity of the enzyme at 350 nm does not show considerable change at pH 3.5-7.0.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1479-1484
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• 2008

This study was conducted to investigate the quality characteristics of fermented-defatted soybean grits (DSG). Fermented-DSG was prepared by inoculating Bacillus subtilis NUCI into steamed DSG at 2% (v/w) concentration and fermenting at $40^{\circ}C$ for 24 hr. The protein contents of DSG and fermented-DSG were higher by $57.2{\sim}61.0%$ than those of Chungkukjang, but lipid contents of these samples were not detected. The protease and $\alpha$-amylase activities, and solid contents in DSG were not shown. However, the activities of protease and $\alpha$-amylase, tyrosine contents, fluid consistency, and viscous substance contents of fermented-DSG were higher than those of Chungkukjang. The levels of free amino acids and isoflavone of fermented-DSG tended to increase more than those of DSG. The sensory score of fermented-DSG were higher in odor and taste than those of Chungkukjang groups, while lower in color and overall acceptability.

• Culinary science and hospitality research
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• v.6 no.3
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• pp.357-371
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• 2000

Changes of Microflora, enzyme activity, and contents of several taste compounds in traditional Kanjang(Korean Soy Sauce) with the variation of fermentation jars and Meju(fermented soybean brick)concentration were studied. Substitution possibilities of clay jar with glass jar and improvement possibilities of taste and nutritional value with increased Meju concentration were examined. (1) Aerobic bacteria and lactic acid bacteria were enumerated during fermentation and ripening period. But yeast and molds were hardly isolated. The number of viable cells showed small changes during fermentation and ripening period. (2) Isolated Aerobic bacteria were identified as Bacillus subtilis, Bacillus lichenformis, and lactic acid bacteria were identified as Lactlbacillus lactis lactis and lactobacillus brevis. (3) The activities of $\alpha$-amylase and $\beta$-amylase increased during fermentation period, but did not show any trend by fermentation jars or Meju concentrations. Protense activity showed small difference among four samples, and increased during the fermentation period.

• Korean Journal of Food Science and Technology
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• v.21 no.5
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• pp.686-690
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• 1989

Non sticky short grain rice was liquidized by ${\alpha}-amylase$ from Bacillus species after cooking 20min at $121^{\circ}C$ and a lactic acid bacteria fermentation proceeded. The product using mixed culture of S. thermophilus, L. bulgaricus and L. plantarum was superior than the one of any single or mixed culture. The most acceptable pH of it was 3.70. It is suggested that L. plantarum is more deeply related to the product quality. Skim milk promoted lactic acid fermentation but the quality of the final product was not acceptable in the result of sensory evaluation. The acceptable dilution rate of final product was 1:3 (rice: water) by weight.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.757-763
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• 2010

The qualities of Deodeok Doenjang including physicochemical characteristics and sensory properties were investigated over the following range of Deodeok levels: 5, 10, 15 and 20% (all w/w). The strains used in the manufacturing of Doenjang were Bacillus sp. B-3 and Aspergillus sp. M-9 with the highest enzyme activities like amylase and protease. In case of Deodeok Doenjangs prepared with Bacillus sp. B-3, the amino-type nitrogen of Doenjang containing 10% (w/w) Deodeok was produced more than others during fermentation for 40 days. Amino-type nitrogen produced in Deodeok Doenjang prepared with Aspergillus sp. M-9 was more than one of Deodeok Doenjangs with Bacillus sp. B-3 and a commercial Doenjang. When Deodeok content exceeded 15% (w/w), higher content resulted in lesser amino-type nitrogen production. The results showed that Deodeok had influenced growth of Bacillus sp. and Aspergillus sp. Sensory evaluation showed that Deodeok Doenjangs containing 10% (w/w) Deodeok and 1% (w/w) Bacillus sp. B-3 and containing 20% (w/w) Deodeok and 1% (w/w) Aspergillus sp. M-9 were superior to the other Doenjangs tested.

• The Korean Journal of Food And Nutrition
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• v.26 no.2
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• pp.273-279
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• 2013

The microorganisms producing high protease activity and acid producing ability were isolated from Chunggukjang and kimchi, which were identified as Bacillus subtilis and Lactobacillus planetarum by morphological, biochemical and nutrient requirement. The attempt was made to produce soybean milk yoghurt by using the isolated microorganisms. The mixed culture of Bacillus subtilis and Lactobacillus plantarum exhibited the lowest pH value of 4.23 and highest titratable acidity of 0.88% compared to those of single cultures at $37^{\circ}C$ for 32 hrs, and their total viable count was $4.09{\times}10^8$ $cfu/m{\ell}$. The ${\alpha}$-amylase activity was the highest in culture of Bacillus subtilis after incubation for 24 hrs, while protease activity was most produced in mixed culture of Bacillus subtilis and Lactobacillus plantarum. The amounts of reducing sugars were steadily decreased as soy milk fermentation progressed.

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.179-185
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• 2009

Soybean grits, fortified with various bioactive components, were produced by solid-state fermentation using Bacillus subtilis HA. ${\alpha}$-Amylase activity gradually increased during fermentation over 5 days. Fibrinolytic and protease activities were highest in the soybean grits fermented for 7 days. The grits fermented for 5 days also showed the highest tyrosine content, indicating a higher peptide content. Peptides of low molecular weight (below 3,000 daltons) and browning pigments increased with increasing fermentation time. The fermented soybean grits showed higher contents of total phenolic compounds, to approximately 18 mg/g. DPPH free radical scavenging effects were higher in the soybean grits fermented for 3 days. Also, ABTS radical scavenging effects were greater in the fermented grits compared to the unfermented grits. Overall, the soybean grits fermented by solid-state fermentation for 5 days showed enhanced production of bioactive compounds and greater antioxidant properties.