• 한국식품과학회지
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• 제15권4호
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• pp.399-403
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• 1983

청국장 발효과정중에 일어나는 지질성분(脂質成分)의 변화(變化)를 규명하고저 삶은콩에 Bacillus natto 를 접종(接種), 3일간 발효시킨후 식염을 7% 첨가하여 20일간 숙성(熟成)한 청국장을 만들고, 삶은콩, 청국장 고오지 및 청국장제품의 지질(脂質)에 관한 연구를 행하여 다음과 같은 결과를 얻었다. 삶은콩의 총지질(總脂質) 함량중 중생지질(中性脂質)은 92.08%, 유리지방산(遊離脂肪酸)은 1.76%, 당지질(糖脂質)은 2.04%, 연지질(憐脂質)은 4.12% 이었으나, 발효숙성(醱酵熟成)과정중 중성지질(中性脂質)이 감소하고 유리지방산(遊離脂肪酸) 함량이 증가하였으며 당지질(糖脂質)의 함량도 증가하는 경향을 나타냈고 연지질(憐脂質)의 함량은 청국장 고오지 발효중에 증가하였다가 숙성기간중 감소하였다. 또한 연지질(憐脂質)과 당지질획분(糖脂質劃分)들의 발효숙성중(醱酵熟成中)의 구성성분의 변화에 있어서 특히 포스파티딜 이노시톨 및 포스파티딜 콜린의 변화가 주목되었고 또 디-갈락토실 디-글리세리드가 현저하게 감소되었다. 한편, 중성지질(中性脂質) 및 유리지방산(遊離脂肪酸)들의 구성 지방산(脂肪酸)중 주요성분은 리놀레산이었으며 당지질(糖脂質)과 연지질(憐脂質)에서는 팔미트산이었고 특히, 다른 지질획분(脂質劃分)에 비해 당지질(糖脂質)에는 리놀렌산 함량이 거의 없는 것으로 나타난다. 발효숙성(醱酵熟成) 결과 연지질(憐脂質) 및 당지질획분(糖脂質劃分)들에서 포화지방산(脂肪酸) 함량이 감소한 반면 불포화도가 높은 지방산(脂肪酸)의 함량은 증가하였다.

• 한국식품과학회지
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• 제14권4호
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• pp.309-314
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• 1982

Bacillus natto 및 Bacillus subtilis 균(菌)을 이용한 방법 및 볏짚을 이용한 재래식 방법에 따라 제조한 청국장의 저장(貯藏)과정 중 성분변화를 측정한 결과는 다음과 같다. 1. 저장(貯藏) 중 pH는 대체로 저하(低下)하는 경향을 보여 저장(貯藏) 18일 후에는 7.0 이상으로 나타났고 식염(食鹽)은 $5.28{\sim}6.4%$ 사이였으며 적정산도(滴定酸度)는 B. subtilis 구(區)가 최대치(最大値)를 나타냈다. 2. 수분함량(水分含量)은 $50.94{\sim}56.74%$를 보였고 조단백함량(粗蛋白含量)은 $14.44{\sim}18.60%$로서 시험구에 따라 다소 차이가 있어 불규칙적인 증감현상을 보였다. 이에 반해 조지방(粗脂肪)과 조섬유(粗纖維)는 대체로 감소하는 경향이었다. 3. 총당(總糖)과 ethyl alcohol함량(含量)은 시험구 모두 감소하는 경향이었는데 저장(貯藏) 18일후에 총당(總糖)은 B. subtilis구(區)가 가장 낮았다. 4. 아미노태(態) 질소(窒素)와 수용성질소(水溶性窒素)의 함량(含量)은 경시적으로 증가하는 경향이었으나 각 시험구간의 차이는 없었다. 5. Amylase와 Protease의 활성(活性)은 경시적으로 불규칙적인 변화를 보여 각 시험구간에 큰 차이가 없이 대체로 미약(微弱)하였다.

• Food Science and Biotechnology
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• 제17권1호
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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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• 제9권2호
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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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• 제9권1호
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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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• 제16권4호
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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.

• 농업과학연구
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• 제49권4호
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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.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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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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• 제12권4호
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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.

• 한국식품조리과학회지
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• 제23권3호통권99호
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• pp.288-293
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• 2007

청국장을 이용하여 마가린, 버터 대용품을 개발하고자 하였다. 청국장 고유의 냄새는 동결건조 마늘을 처리하여 발효과정에서 제거가 가능하였다. 청국장이 갖고 있는 고유의 높은 점도로 인하여 흐름성이 매우 낮아 물질을 제조하는데 어려움이 있었으나 이는 3%(w/w) 수준의 대두유 처리로 개선할 수 있었다. 이 과정에서 trans 지방산 함량의 변화를 측정한 결과 초기 0.02${\sim}$0.05%로 일반적인 마가린, 버터에 비하여 아주 낮은 trans 지방산 함량을 나타내었고, 저장 4주 후에도 0.03${\sim}$0.08%로 거의 검출 허용 한계치의 수준을 보였다 따라서, 동결건조 마늘을 처리하여 일부 젊은 층에서 기피해 오던 고유의 냄새를 없앤 청국장과 대두유를 사용하여 제조한 마늘 청국장 페이스트의 상용화가 가능할 것으로 판단된다.