• Korean Journal of Food Science and Technology
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• v.15 no.4
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• pp.399-403
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• 1983

Chungkookjang, a traditional Korean fermented soybean food, was prepared by a commercial process. Cooked soybeans were fermented with Bacillus natto for 3 days and ripened with addition of 7% salt for 20 days. And the changes in the lipids during these chunqkookjang fermentation were studied. The total lipid content was decreased during chungkookjang preparation from 12.1% to 9.5%. Total lipid of cooked soybean consisted of 92.08% neutral lipids, 1.76% free fatty acids, 2.04% glycolipids and 4.12% phospholipids, respectively. During fermentation, as netural lipids were decreased, contents of free fatty acids and glycolipids were increased. The changes of phosphatidyl inositol and phosphatidyl choline in phospholipid fraction were observed and digalactosyl diglyceride in glycolipids fraction was significantly decreased during fermentation. Difercences were observed in the fatty acid compositions of glycolipids and phospholipids of cooked soybeans and chungkookjang. Oleic acid was the major fatty acyl moiety in neutral lipid and free fatty acid fractions, and palmitic acid was predominant in glycolipids and phospholipids. During fermentation, saturated fatty acyl moieties of glycolipids and phospholipids were increased.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.309-314
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• 1982

The growth process of the Chungkook-jang that occured by utilizing such traditional methods as Bacillus natto and Bacillus subtilis method has been examined. The results of the experiment in which the changing process of elements during the storage period had been measured are as follows: 1. During the growth period, concerning any change in pH, the storage period had been declined and after 18 days pH rose above 7.0. Salt content was between $5.28{\sim}6.40%$ and Bacillus subtilis fungus showed the highest titrable acidity. 2. Moisture content was between $50.94{\sim}56.74%$ and crude protein content range was $14.44{\sim}18.60%$ indicating irregularity in pattern resulting from the testing equipment groups, whereas crude fat and crude fiber tend to decrease in general. 3. During the storage, total sugar and ethyl alcohol content in all of groups tended to decrease and after 18 days Bacillus subtilis total sugar content was the lowest. 4. Amino nitrogen and water soluble nitrogen content increased with days, but no difference was found between groups. 5. Amylase and protease activity showed irregular pattern with time, but no significant difference between groups was found.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.172-175
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• 2008

Two new fermentation products were separated from cheonggukjang by high performance liquid chromatography (HPLC) and tentatively identified as succinyl daidzin and succinyl genistin by HPLC-mass spectrometry (MS). Both succinyl daidzin and succinyl genistin were detected in all 4 commercially available and one laboratory prepared cheonggukjang and 1 commercially available natto. However, these compounds were not detected in commercially available 4 home-made and 4 factory-produced doenjang. Peak areas of succinyl genistin were about 1.95-2.45 times higher than those of succinyl daidzin in cheonggukjang, which may be due to the higher concentration of genistin derivatives than daidzin derivatives in soybeans. This is the first report on the succinyl derivatives as isoflavone metabolites from cheonggukjang and these 2 isoflavone derivatives could be characteristic indicators for cheonggukjang.

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.230-233
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• 1999

A plasmid vector was constructed for the expression and secretion of Bacillus macerans cyclodextrin glucanotransferase (CGTase) in Bacillus subtilis. The vector, pUBACGT, was composed of the ribosome-binding sequence, signal sequence, and cgt gene from B. macerans under the control of amyR2, the promoter of amyE gene coding for $\alpha$-amylase from B. subtilis var. natto. Bacillus subtilis LKS88, a mutant strain lacking genes for an amylase and two proteases, was used as a host for the transformation of the plasmid vector. The transformants were selected on kanamycin-containing Luria-Bertani plates. The starch hydrolyzing activity was observed on the starch-containing plates by the iodine method and cyclodextrin-forming activity was detected in the culture medium. A SDS-PAGE analysis showed that most of the expressed CGTase in the recombinant B. subtilis was secreted into the medium at a high expression level.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.14-20
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• 2004

Bacillus strains capable of producing fibrinolytic enzyme were isolated from traditional fermented Korean soybean paste and Japanese fermented soybean (Natto). Among the 16 strains, a selected Bacillus sp. was identified as bacillus firmus, with 80.7％ homology, by API kit analysis. Seed starter or B. firmus NA-1 was prepared with 5％ soymilk prepared from micronized soybean powder. To produce fibrinolytic enzyme by B. firmus NA-1 the liquid culture was performed with NB broth (pH 7.0) fortified with 1％ galactose, 0.1% tryptone, and 0.5% $K_2$HPO$_4$, by shaking with 180 rpm at 37$^{\circ}C$. Fibrinolytic enzyme activity reached the highest value at 7.8 unit/mL (plasmin unit) after fermentation for 72 hr. The crude fibrinolytic enzyme showed higher relative activity in the range of pH 7.0∼9.0. The activity of crude fibrinolytic enzyme was well maintained even after concentration by the vacuum evaporation at 5$0^{\circ}C$ for 1 hr.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.655-658
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• 2007

Bacillus polyfermenticus SCD was transformed by the recombinant shuttle vector for Bacillus and Escherichia coli containing 3 antibiotic resistant genes and an ${\alpha}$-amylase gene from Bifidobacterium adolescentis Int57. The ${\alpha}$-amylase gene fused to a secretion sequences was expressed under the control of the promoter of amylase gene from B. subtilis var. natto. The recombinant plasmid was maintained stably in the transformants producing the ${\alpha}$-amylase. The enzyme was secreted to outside of the cell and showed the similar enzyme activity as that of Bacillus subtilis BD170 under the same conditions of pH and growth temperature. Because of the relatively easy transformation and the secretion of the enzyme, the transformants of B. polyfermenticus SCD may give a new strategy in the production of foreign genes.

• Korean Journal of Agricultural Science
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• v.49 no.4
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• pp.995-1001
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• 2022

The purpose of this study was to compare the effect of solid-state fermentation on soybean using three microbial strains under four different fermentation times. Soybean was fermented for 12, 24, 36 or 48 hours with highly proteolytic microbes, either Bacillus amyloliquefaciens (BA), B. subtilis (BS), or B. subtilis var. natto (BN), and levels of total protein concentration, protein distribution, and antioxidant activity were analyzed. Total protein was highest in the BS 12 h group (9.21 ㎍·µL^-1) and lowest in BN 48 h (6.80 ㎍·µL^-1), respectively (p < 0.001). Furthermore, three microbes decomposed large molecular weight proteins as well as major allergens of soybean such as β-conglycinin, Gly m Bd 30K, and glycinin. Each treatment group showed the highest degradation rate at 48 h fermentation and among the three microbes, BS showed a relatively higher degradation rate. The radical scavenging ability, known as an indicator of antioxidant activity, showed a significant increase in all treatment groups except BA 24 h. The results from this study suggest that protein concentration, and degradation and antioxidant activity were affected by different types of microbial trains and fermentation period and that B. subtilis fermentation might be the most effective way to increase nutritional and functional properties of soybean.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.223-223
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• 2022

Saengcheonggukjang, known as Natto in Japan, is a Korean fermented soybean food that has various bioactive compounds for antioxidant and antidiabetic activity. The development of soybean (Glycine max L.) cultivars for saengcheonggukjang production relies on the selection of seed traits that influence the quality and sensory properties. One of the important traits for cultivars is seed characteristics such as seed hardness and size. In order to select the lines for breeding good quality saengcheonggukjang varieties, several simple sequence repeat (SSR) markers and quantitative trait loci (QTLs) related to seed quality of Korean cultivars, Pungsannamulkong, Socheongja, Pungwon, Heawon, and Hoseo, were analyzed. Based on the many studies to detect stable QTLs for seed traits, we tested several QTLs related to seed size and water absorbability using SSR markers on Korean cultivars. The results showed that two regions for water absorbability of Pungsannamulkong and one region for seed size traits of Haewon and Hoseo were identified in this study. These results could have applications to soybean breeding for seed size and hardness and it is necessary to narrow it down through further study.

• Journal of Microbiology and Biotechnology
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• v.12 no.4
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• pp.649-656
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• 2002

Fibrinolytic microorganisms were screened from 42 samples of Korean fermented food (7 kinds of Chungook-jang, 14 kinds of commercial Doen-Jang, 5 kinds of home-made Doen-jang, and 16 kinds of Jeot-gal), 15 samples of Japanese fermented food (5 kinds of home-made soybean paste, and 10 kinds of Natto), and 19 samples of Indonesian fermented food (Tempe) as well as starters of Meju (500 microflora from Korea, and 22 from China). Initially, 11 isolates with strong fibrinolytic activity were selected for further characterization. The fibrinolytic activity of the 11 isolates ranged from 89 to 199% of standard plasmin. Four strains, M5l from Korean fermented food (Meju), I 1-1, I 1-4, and I 5-1 from Indonesian fermented food (Tempe), were chosen based on the degree of activity and reproducibility, and identified as Staphylococcus sciuri, Citrobacter or Enterobacter, Enterococcus faecalis, and Bacillus subtilis, respectively. The first two isolates are pathogenic stains while the latter two are considered as GRAS (Generally Recognized As Safe). Fibrinolytic activity of E. faecalis, characterized and designated as BRCA-5, reached a maximum, when the producer was cultivated in Ml7 broth supplemented with 1.0% glucose for 5 h at 37$^{\circ}C$ with shaking at 180 rpm. Compared to commercial fibrinolytic enzymes, the cell-free culture supernatant of 5. faecaiis BRCA-5 showed stronger activity than plasmin and streptokinase, but similar degree of specific activity as nattokinase and urokinase, aud it also demonstrated anticoagulant and antiplatelet activity ex vivo. These features of E. faecalis make it an attractive agent as a biomaterial for health-promoting foods.

• Korean journal of food and cookery science
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• v.23 no.3 s.99
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• pp.288-293
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• 2007

In this study, chunggukjang was made from soybeans and Bacillus natto. This chunggukjang was meant to be consumed as a margarine and butter substitute, to help lower trans-fatty acid (TFA) intake. A freeze-dried garlic product was used during fermentation to aid in removing the smell of the chunggukjang. Chunggukjang has a very low fluidity due to its high viscosity; therefore, we added 3%(w/w) soybean oil to improve the fluidity. We found that the TFA content of the garlic chunggukiang paste was no more than 0.02${\sim}$0.05%, which was low compared to the usual contents of margarine and butter. After 4 weeks of storage the TFA content was 0.03${\sim}$0.08%, and it remained within the limits of the permissible amount. The addition of soybean oil allowed this chunggukjang to be made with greater ease, and the freeze-dried garlic eliminated the negative inherent qualities of the chunggukjang. Therefore, this garlic chunggukjang paste could be considered reasonable for commercial production.