• Journal of Microbiology and Biotechnology
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• v.27 no.5
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• pp.896-908
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• 2017

In this study, a total of 58 different kinds of nuruk (a traditional Korean fermentation starter) were prepared, including 46 kinds of restored nuruk from ancient documents. Each nuruk was evaluated by analysis of its saccharification power, and the enzyme activities of glucoamylase, ${\alpha}$-amylase, ${\beta}$-amylase, protease, and ${\beta}$-glucanase. The range of saccharification power (sp) of the restored nuruk ranged between 85 and 565 sp. The diastatic enzymes, ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase, were significantly correlated to the saccharification power value; conversely, ${\beta}$-glucanase and protease did not have a correlative relationship with saccarification power. In addition, their brewing properties on chemical and organoleptic aspects of traditional alcoholic beverage production were compared. Each raw and supplementary material contained in nuruk showed its own unique characteristics on Korean alcoholic beverage brewing. For the first time, in this study, the traditional Korean nuruk types mentioned in ancient documents were restored using modernized production methods, and also characterized based on their brewing properties. Our results could be utilized as a basis for further study of traditional alcoholic beverages and their valuable microorganisms.

• Korean Journal of Food Science and Technology
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• v.22 no.5
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• pp.533-538
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• 1990

In polysaccharide fermentation with Aureobasidium pullulans, the aeration effects on the production of polysaccharide and the rheological properties of fermentation broth were studied. The increase of the aeration rates from 0.5 to 2.0vvm at 500 rpm yielded the maximum specific production rate of polysaccharide from 0.046 to $0.093 (hr^{-1})$, and the maximum specific growth rate of cells from 0.168 to $0.192 (hr^{-1})$. The viscosity behavior of fermentation broths at the different aeration rates followed the power-law ${\tau}= K({\gamma})^n$. The viscosity attributed by cells was about 10% of the total viscosity of fermentation broth and most of viscosity was attributed by the polysaccharide produced. The relationship between power-law parameters and the concentration of polysaccharide generally satisfied the etㄴrations with the regression coefficient greater than 0.980, $lnK(t)= ln({\tau})_o-n(t)\;ln({\gamma})_o\;and\;K(t)=A P(t)^B$.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.5
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• pp.776-782
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• 2009

This study was conducted to develop functional soybean paste with krill (Euphausiacea) as compared to a conventional soybean paste (S1). Soybean containing 10%, 20% and 30% (w/w) krill (S2~S4, respectively) was prepared and quality characteristics (moisture, crude fat, crude protein, ash, reducing sugar, pH, titratable acidity, total acidity and buffering power) were assessed during fermentation for 150 days. As well, antioxidative activities of krill soybean paste were compared to those of control soybean paste based on total phenolic compound content and free radical scavenging activity, including the 1,1-diphenyl-2-picryl-hydrazil (DPPH) scavenging activity and the thiobarbituric acid value (TBA value). The moisture content of all samples decreased to 41.91~53.47% during fermentation, while the crude fat increased to 1.98~5.21% with increasing addition of krill. Additionally, crude protein increased slightly to 8.24~14.08% with increasing addition of krill after 120 days of fermentation. Ash content was 15.96~18.92%. The reducing sugar content of S2, S3 and S4 was higher than those of S1 with increasing length of fermentation. S2, S3, and S4 displayed progressive decreases in pH and progressive increases in titratable acidity compared to S1. The total acidity of all samples was increased, while the buffering power was decreased with increasing fermentation. Especially, the buffering power of S1 was lower than that of S2, S3 and S4. DPPH radical scavenging activity of lipophilic extracts from S2, S3 and S4 was slightly higher than those of S1. However, the radical scavenging activity of hydrophilic extracts from all samples had similar tendencies, regardless of the krill content or fermentation period. Total phenolics increased with increasing fermentation time and TBA value increased with increasing fermentation time and krill content.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.659-664
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• 1994

In order to predict gas hold-up and oxygen transfer rate during sisomicin fermentation employing air lift fermentor, simulated media similar to fermentation broths in rheological proper- ties were prepared and used. Rheological properties of fermentation broths from 40 hours and 60 hours of cultivation were analyzed by applying to Power's Law equation. Regardless of addition and no addition of MgSO$_{4}$, the tendencies, that n value was decreased and K value was increased as aeration rate was increased, were shown. Simulated media of twelve different fermentation broths were formulated in a range of 0.7 to 2.1% CMC, and the values of gas hold-up and k$_{L}$a depending on superficial air velocity were measured using these simulated media. And the relation- ships, $\varepsilon$=$\alpha$U$_{Gr}$$\beta$, K$_{L}$a=$\gamma$U$_{Gr}$$\delta$ were obtained, and these equations are thought to be used to predict the values of gas hold-up and k$_{L}$a during fermentation.

• Journal of Applied Biological Chemistry
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• v.59 no.1
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• pp.57-62
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• 2016

In this study, we optimized fermentation conditions for the solid state fermentation of rice bran with Monascus pilosus KCCM60084, and the antioxidant activities were investigated. Optimal fermentation conditions were determined by the production of Monacolin K, a functional secondary metabolites with cholesterol lowering activity. The highest Monacolin K production were 2.88 mg/g observed on day 10 with 45% moisture content in the substrate when inoculated with 5% inoculum (w/w). Reducing power, iron chelating activity and $ABTS^+$ radical scavenging activity were significantly enhanced after fermentation by 60, 80, and 38% respectively. Furthermore, the content of total flavonoid were found to be increased by 4.58 fold. Based on these results, Monascus-fermented rice bran showed strong possibility to be used as a natural antioxidant agent due to its enhanced antioxidant activity.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.101-108
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• 2015

Objectives : Positive effects of Ginseng has great research attentions such as anticancer, anti-diabetic, antiaging, liver, immune function, CNS, etc. In this study, we investigated Hydroponic-cultured Ginseng Folium fermented byBacillus subtilisto establish fermentation conditions for enhancing functionality.Methods : Ginseng Folium were cultivated hydroponic-cultured and were extracted with methanol. We inoculateBacillus subtilisfor fermentation by adding to 0%, 3% and 5% sugar respectively and checked antioxidant activities, total phenolic content and total saponin content in 2 days intervals during 11 days. The antioxidant activities were studied by the 1,1-diphenyl-2-picryl hydrazyl(DPPH) radical, 2, 2'-Azino-bis(3-ethylbenzothiazoline-6 sulfonic acid) diammonium salt(ABTS) radical scavenging assay and Reducing power assay. We analyzed the Total phenol content, crude saponin content and ginsenoside content. Moreever, Hepatoprotective effects by Glutamic oxaloacetic transaminase(GOT) and Glutamic pyruvic transaminase(GPT) in Sprague-Dawley rat.Results : The results of DPPH and ABTS were 66.89% and 96.72%, respectively. The reducing power was resulted in optical density of 0.7312 with 3% sugar after 9 days of fermentation. and the concentration at 200 ㎍/㎖. Total phenol content was 36.92㎎/g with 3% sugar after 9 days of fermentation, in which crude saponin content wasn't changed, and ginsenoside content such as Rg3, Re and Rb was increased. Activities of GOT and GPT concentration were decreased in rat.Conclusions : This study suggests that hydroponic-cultured Ginseng Folium fermented byBacillus subtilisin 9 days showed significant efficacy of hepato-protection as well as antioxidant compared to the others. In addition, it shows not only improved value but also utilized hydroponic-cultured Ginseng Folium by fermentation.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.52-58
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• 2006

Characteristics of dough added with up to 4.0% takju powder and resultant bread were studied. Doughs added with takju power spray-dried after fermentation with starter (SDWS) and takju power spray-dried after fermentation without starter (SDOS) showed higher pH decreases than those added with takju power freeze-dried after fermentation with starter (FDWS) and takju power freeze-dried after fermentation without starter (FDOS) even after 1st fermentation. After 1st fermentation, volume of dough added with 1-4% SDWS was high, with 1% SDWS showing highest value of 23.6 mL. Volume of bread added with SDOS showed highest value. At 1-2% SDWS and SDOS addition, doughs showed highest specific volume values, which decreased at higher than 3% addition, while specific volume increased with increasing FDWS and FDOW contents. L values of SDOS- and FDOS-added doughs decreased gradually with increasing SDOS and FDOS contents compared to SDWS and FDWS addition. In loaf bread added with takju powder less than 2%, loaf bread added with spray-dried takju powder had higher appearance, color, texture, taste, and overall acceptability values compared to those added with freeze-dried takju. Although not significantly, loaf bread added with 1% SDWS showed slightly higher values in appearance, color, yeastiness, texture, taste, and overall acceptability, and showed higher flour odor acceptability than non-added loaf bread. These results indicate addition of takju powder improves flavor of bread.

• Journal of Microbiology and Biotechnology
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• v.20 no.7
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• pp.1092-1100
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• 2010

Bacteria, fungi, and protozoa inhabiting the rumen, the largest chamber of the ruminants' stomach, release large quantities of hydrogen during the fermentation of carbohydrates. The hydrogen is used by coexisting methanogens to produce methane in energy-yielding processes. This work shows, for the first time, a fundamental possibility of using a hydrogen-rich fermentation gas produced by selected rumen ciliates to feed a low-temperature hydrogen fuel cell. A biohydrogen fuel cell (BHFC) was constructed consisting of (i) a bioreactor, in which a hydrogen-rich gas was produced from glucose by rumen ciliates, mainly of the Isotrichidae family, deprived of intra- and extracellular bacteria, methanogens, and fungi; and (ii) a chemical fuel cell of the polymer-electrolyte type (PEFC). The fuel cell was used as a tester of the technical applicability of the fermentation gas produced by the rumen ciliates for power generation. The average estimated hydrogen yield was ca. 1.15 mol $H_2$ per mole of fermented glucose. The BHFC performance was equal to the performance of the PEFC running on pure hydrogen. No fuel cell poisoning effects were detected. A maximum power density of $1.66\;kW/m^2$ (PEFC geometric area) was obtained at room temperature. The maximum volumetric power density was $128\;W/m^3$ but the coulombic efficiency was only ca. 3.8%. The configuration of the bioreactor limited the continuous operation time of this BHFC to ca. 14 h.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.554-558
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• 1999

Flow properties of traditional kochujang at various fermentation times(0~12 weeks) were determined with rotational cylindrical(RC) and serrated plate plate(PP) viscometer. Magnitudes of consistency index(K) of power law model and Cassson parameters(yield stress and viscosity) measured by PP viscometer were higher than those using RC viscometer. All kochujang samples during fermentation were much shear thinning with values of flow behavior index(n) as low as 0.2~0.34. K value and Casson yield stress measured by PP viscometer had good correlations(r=0.94; r=0.91) with fermentation time. No significant changes in flow model parameters measured by RC viscometer were observed for kochu jang during fermentation. Magnitudes of flow model parameters measured by PP viscometer more closely correlated with fermantation times of kochujang than did RC viscometer.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.2
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• pp.225-234
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• 2006

Characteristics of electricity production from major fermentation products (acetate, propionate and butyrate) were evaluated in a microbial fuel cell (MFC). For each substrate, batch and continuous experiments were performed. The batch test result indicated that coulombic efficiency depended on the resistance connected in MFC circuit. With acetate, coulombic efficiency were 87% at $20{\Omega}$, but decreaced to 45% at$220{\Omega}$. In continuous tests, maximum power densities obtained was 220 Q with acetate. The maximum power densities of butyrate, acetate and propionate were 6.8, 6.1, and $5.2mW/m^2$, respectively. Propionate and butyrate were converted into acetate producing high currents. $H_2$ produced during butyrate and propionate probably used to produce electricity. In conclusion, butyrate conversion into acetate was faster than that of propionate with higher electricity production. If the production of propionate is inhibited during fermentation, anaerobically fermented liguor may be effectively applied for MFC.