• Journal of Microbiology and Biotechnology
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• 제27권1호
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• pp.57-66
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• 2017

Aflatoxins are classified as Group 1 (carcinogenic to humans) by the International Agency for Research on Cancer. In this study, a total of 134 fungal strains were isolated from 65 meju samples, and two fungal isolates were selected as potential aflatoxin $B_1$ ($AFB_1$)-biodetoxification fungi. These fungi were identified as Aspergillus oryzae MAO103 and A. oryzae MAO104 by sequencing the beta-tubulin gene. The two A. oryzae strains were able to degrade more than 90% of $AFB_1$ (initial concentration: $40{\mu}g/l$) in a culture broth in 14 days. The mutagenic effects of $AFB_1$ treated with A. oryzae MAO103 and MAO104 significantly decreased to 5.7% and 6.4%, respectively, in the frame-shift mutation of Ames tests using Salmonella typhimurium TA98. The base-substituting mutagenicity of $AFB_1$ was also decreased by the two fungi. Moreover, $AFB_1$ production by Aspergillus flavus was significantly decreased by the two A. oryzae strains on soybean-based agar plates. Our data suggest that the two $AFB_1$-detoxifying A. oryzae strains have potential application to control $AFB_1$ in foods and feeds.

• Journal of Microbiology and Biotechnology
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• 제22권11호
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• pp.1510-1517
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• 2012

To evaluate the probiotic potential of Bacillus polyfermenticus CJ6 isolated from meju, a Korean traditional soybean fermentation starter, its functionality and safety were investigated. B. polyfermenticus CJ6 was sensitive to all antibiotics listed by the European Food Safety Authority. The strain was also non-hemolytic, carried no emetic toxin or enterotoxin genes, and produced no enterotoxins. The resistance of B. polyfermenticus CJ6 vegetative cells and spores to simulated gastrointestinal conditions was high (60-100% survival rate). B. polyfermenticus CJ6 produced high amounts (0.36 g as a purified lyophilized form) of ${\gamma}$-polyglutamic acid (PGA). We speculate that the improved cell viability and the production of ${\gamma}$-PGA have a significant correlation. Adhesion of the strain to Caco-2 and HT-29 cells was weaker than that of the reference strain (Lb. rhamnosus GG), but it was comparable to or stronger than those of reported Bacillus spp. When B. polyfermenticus CJ6 spores were given orally to mice, the number of cells excreted in the feces was 4-fold higher than the original inocula. This suggests the inoculated spores propagated within the intestinal tract of the mice. This idea was confirmed by field emission scanning electron microscopy, which revealed directly that B. polyfermenticus CJ6 cells germinated and adhered within the gastrointestinal tract of mice. Taken together, these findings suggest that B. polyfermenticus CJ6 has probiotic potential for both human consumption and use in animal feeds.

• 한국식품영양과학회지
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• 제26권5호
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• pp.775-783
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• 1997

Morphologically different 18 strains were isolated and examined for their abilities to inhibit ACE. Those strains were cultured in the medium containing 10% of soybean extract at 37$^{\circ}C$ for 48hr or fermented with boiled soybean at 3$0^{\circ}C$ for 60 days. The concentration of inhibitors to inhibit 50% of ACE activity, $IC_{50}$ was measured on the culture broth of each strain and also on the hot-water extract from 20, 40 and 60 day fermented Doenjang by each strain. As a result, SCB-3 which is isolated from Meju showed the highest ACE inhibitoryactivity on the cultured broth and 40 day matured Doenjang. Then, $IC_{50}$ of SCB-3 was 0.02 mg/ml and 0.26mg/ml respectively. SCB-3 was identified as a Bacillus subtilis based upon its morphological, biochemical and physiological properties. Changes in general components and ACE inhibitory activity of Doenjang fermented by SCB-3 were examined during 90 days. Total acidity of Doenjang was increased from 1.39% to 1.66% and pH was decreased from 6.02 to 5.79 after 90 days fermentation. Total sugar contents were decreased from 16.4% to 15.1% and reducing sugar contents was also decreased from 2.45% to 1.62%. Total nitrogen contents were nearly not changed, but amino nitrogen contents were drastically increased from 196mg% to 541mg%. The numbers of total microorganism were increased to 1.1$\times$$10^{8}$ cells/g after 45 days. Protease activity was increased to 622.1U/g after 75 days. The highest ACE inhibitory activity was shown in 60 day fermented Doenjang and $IC_{50}$ of the hot-water extract was 0.31mg/ml.

• 한국지역사회생활과학회지
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• 제14권3호
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• pp.89-98
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• 2003

To assess the actual status of businesses selling fermented soybean products, this study surveyed 130 Farmhouse style small size soybean sauce processing sites supported by the Rural Development Administration nationwide. The sex composition of the businesses representatives of 2% male and 98% female showed that a farmhouse soybean processing business is generally operated by rural women as a non-filming business. The percentage of co-worked sites was 71.2 and that of sites with permits was 39.2. The main products were meju, doenjang, and kanjang. Total production volume was found to be 523 tons, 256 tons, and 135 k$\ell$s, respectively. The number of years of experience of the manufacturers of the kanjang and doenjang was found to be 25.7 on average which shows that long-experienced, skilled manufacturers are participating in this project. The traditional measuring unit differed greatly depending on the region. This difference in the measuring unit of soybeans resulted in a large difference in the volume of doenjang and kanjang produced Per Province. For one kg of raw soybeans, the weight of Doenjang produced also varied from 2.14 kg in the Gyeongbuk area to 1.62 kg in Jeju. In the aspect of salt use, 1.75 $\ell$ (translated by volumetric unit 0.704 due) of salt pet kg of meju, in Jeju, was the highest in Korea. Government supervision would be beneficial in the areas of raw material products, standardization of measuring units and production methods, organization and operation of a conference for the different groups of producers, and in construction of a nationwide database.

• 한국식품조리과학회지
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• 제10권1호
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• pp.29-34
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• 1994

In this stydy, Korean traditional Meju adjusted with: the salt contents of 12%, 16%, 20% and the ripeming periods of 90, 135 and 180 days. The results were summerized as follows; 1 The changes of moisture content in soy sauce by 16% salt content was slightly high and the protein was 5.88 by 12%, salt content 2. As the ripening periods was increased, the pH was decreased, on the other hand the total acidity was increased slightly. 3. In the 180 day ripened sample, the salt content increa-sed and the 12% salt content represented 30.6ft salt content. 4. The reduced sugar decreased 135 day ripening, but it increased 180 day ripening at 12fs, 16fs, 20fs salt content. 5. The amino acid content siginificantly decreased by salt content (Serine, Arginine), ripeming periods (Glutamic acid, Asparagine, Glycine, Threomine, Alanine, Methionine, Valine, Isoleucine, Lysine) and ripening time and salt content (Phenylalanine, Leucine) 6. The Fe content decreased 12% salt content while it increa-sed 16% 20% salt content. 7. According to the ripening time, there were significant changes in color, clearance, taste, flavor and over all acceptabilities. As the lower the acceptabilities on flavor or taste increase.

• 미생물학회지
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• 제45권4호
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• pp.377-384
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• 2009

전통 메주로부터 plasmin의 혈전용해 활성보다 약 58% 더 높은 활성을 나타내는 MJ-226을 분리하여 동정한 결과, Bacillus subtilis와 유사한 형태학적, 생화학적 및 당 발효능을 나타내었다. B. subtilis MJ-226은 Tryptic Soy Broth (TSB) 배지 상에서 최대의 혈전용해효소 활성을 나타내었고, $37^{\circ}C$에서 24~26시간 배양했을 때 가장 높은 활성을 나타내었고, TSB 배지 내에 glucose와 fructose 2.0%와 peptone 및 yeast extract 1.0% 각각을 첨가한 경우 활성이 증가되었다. 하지만 lactose, sucrose, beef extract, casein 및 tryptophan 등에 의해선 활성이 오히려 감소되었다. B. subtilis MJ-226이 생산하는 혈전용해효소는 pH 6.0~8.0 및 온도 $35\sim40^{\circ}C$에서 매우 안정하였으며, 또한 $MnSO_4$, $CaCl_2$, KCl 및 NaCl 5 mM 농도의 금속이온에 대해서도 비교적 안정함을 유지하였다. 그러나 $CuSO_4$, $MgSO_4$, $ZnSO_4$, $FeSO_4$와 $BaCl_2$에 등의 금속이온과 iodoacetic acid, leupeptin, phenylmethanesulphonyl fluoride (PMSF), sodium dodecyl sulfate (SDS), thiourea, trans-1,2-diaminocyclohexane-N,N,N',N'- tetraacetic acid (CDTA) 및 ethylenediaminetetraacetic acid (EDTA) 등의 저해제들과 반응한 경우에는 매우 불안정한 것으로 나타났다.

• Food Science and Biotechnology
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• 제17권1호
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• pp.208-211
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• 2008

Previously, it has been reported that Aspergillus oryzae can efficiently degrade unpleasant odor components such as butyric acid and 3-methyl butanoic acid from meju, a major ingredient in both Korean soybean paste (doenjang) and soy sauce. In this study, the optimal manufacturing conditions for the production of superior quality Korean soybean paste and soy sauce were determined. Specifically, A. oryzae AJ 100 was utilized to improve the flavor of these products. Mixtures of Korean soybean paste and A. oryzae AJ 100 culture (2 : 1), and of Korean soy sauce and A. oryzae AJ 100 culture (5 : 1), were incubated for 2 weeks at $30^{\circ}C$, and showed improved flavor. Butyric acid and 3-methyl butanoic acid were clearly degraded under these culture conditions.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.559-562
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• 2000

내염성이며 세포외 protease를 강력하게 생산하는 효모를 재래식 메주효모들과 자연계에서 분리된 내염성 효모들 가운데서 선별하여 Hansenula sp. S-9으로 동정하였다. S-9균주는 $30^{\circ}C$, pH 7.5, 0.5M NaCl을 함유한 배지에서 잘 생육하였고 1.0% beef extract와 1% glucose 및 0.5M NaCl를 함유한 BD배지에서 $30^{\circ}C$로 72시간 배양하였을 때 가장 많은 효소가 생산되었다.

• Food Science and Biotechnology
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• 제14권5호
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• pp.576-580
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• 2005

Ten yeast strains affecting doenjang flavor were isolated from soybean fermented foods (traditional meju and doenjang), among which Zygosaccharomyces sp. Y-2-5, showing excellent growth, glucose consumption, pH, and flavor production, was selected. Higher alcohols produced by Zygosaccharomyces sp. Y-2-5 related to flavor were 2-propanol, 1-propanol, 2-methyl-1-propanol, 1-butanol, and 3.3-dimethyl-2-butanol. Optimal culture conditions for Zygosaccharomyces sp. Y-2-5 were 10% (w/v) NaCl, pH 4.0, 3.0% (w/v) glucose concentration, and inoculation time day 0 or 15 doenjang fermentation.

• KSBB Journal
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• 제16권2호
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• pp.158-162
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• 2001

A halotolerant and extracellular protease-producing yeast was isolated from traditional Meju and identified as a strain of Hansenular polymorpha by investigating its microbiological characteristics. The optimum pH, temperature and NaCl concentration reauired for the growth of Hansenular polymorpha S-9 were found to be pH 6.0, 30$^{\circ}C$ and 0.5 M, respectively. Extracellular protease was produced maximally at 10 U ml(sup)-1 when Hansenular polymorpha S-9 was grown on the medium containing 1.0% beef extract and 0.1 M NaCl for 12 hr at 30$^{\circ}C$. About 13% of the angiotensin-converting enzyme (ACE) inhibitory activity was shown in the hydrolysates which were obtained from the digestion of soybean protein (6 mg) for 6 hr at 30$^{\circ}C$ by the crude enzyme (1 U).