• Food Science and Preservation
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• v.20 no.4
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• pp.573-582
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• 2013

This study was done in order to investigate the bioconversion of ginsenoside, as well as the quality characteristics of fermented ginseng, by using lactic acid bacteria. Quality characteristics such as the thin layer chromatography(TLC) pattern, ginsenosides, total phenolic content, electron donating ability, and total sugar of fermenting ginseng and red ginseng were analyzed. The ginsenoside Rg2r, Rh2s and Rh2r of the fermented ginseng and red ginseng for 65 hours at a temperature of $37^{\circ}C$ were not detected. The ginsenoside Rg1 and Re contents have decreased, while the Rh1, Rg2s, Rd, Rg3r, and Rg3s have increased due to fermentation. The ginsenoside Rg3 of the fermented red ginseng has increased and the contents were $114.83{\sim}131.68{\mu}g/mL$ (control $104.56{\mu}g/mL$). The total phenolic content and electron donating ability of the red ginseng have totally decreased after 7 days of fermentation. The total phenolic contents of the fermented ginseng and red ginseng with different lactic acid bacteria did not show any tendency as different strains. The electron donating ability of the fermented ginseng has increased; however, the electron donating ability of the red ginseng has decreased. The total sugars of the fermented ginseng and red ginseng with different lactic acid bacteria have also decreased.

• Journal of Life Science
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• v.28 no.11
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• pp.1369-1378
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• 2018

Prunus mume Siebold & Zucc., a member of the Rosaceae family (called Maesil in Korea), has been widely distributed in East Asia, e.g. Korea, Japan and China, and its fruit has been used as a traditional drug and health food. In this study, we evaluated physicochemical properties and physiological activities of condensed Prunus mume juice treated with pectinase (PJ). The values of total acidity, pH, sugar contents, turbidity moisture content of the PJ were 35.81%, 2.73, $54.36^{\circ}Brix$, 2.75 and 51.32%, respectively. The PJ had effective DPPH radical scavenging activity, reducing power effect, $H_2O_2$ scavenging activity and ${\beta}$-carotene bleaching effect. DPPH radical scavenging activities of PJ was 46.31%; their reducing power ($OD_{700}$) was 1.80; $H_2O_2$ scavenging activity of PJ was 91.62%; and ${\beta}$-carotene bleaching effect of PJ was 73.02%. Also, PJ showed effective levels of ${\alpha}$-glucosidase inhibition activity. The cell viability was measured by SRB assay. The PJ significantly decreased the cell viability of mouse melanoma cells (B16) and human melanoma cells (SK-MEL-2 and SK-MEL-28) in a dose-dependent manner, however, there was no effect on human keratinocyte HaCaT. In morphological study, PJ-treated SK-MEL-2 cells showed distorted and shrunken cell masses. Total polyphenol contents and total flavonoid contents of PJ were 588.31 mg% (gallic acid equivalent) and 860.45 mg% (rutin equivalent). The antiproliferative effect of PJ seems to be associated with the antioxidant activity of its flavonoid and polyphenol contents. In conclusion, PJ may be beneficial in development of a functional food material.

• Journal of Life Science
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• v.28 no.11
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• pp.1347-1353
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• 2018

The fermentation of non-digestible soy meal can convert polysaccharides into many compounds that have a wide variety of biological functions. Bacillus strains are capable of hydrolyzing non-digestible saccharides, such as melibiose, raffinose, and stachyose, found in soy meal components. A highly active ${\alpha}$-galactosidase (${\alpha}$-d-galactoside galactohydrolase, EC 3.2.1.22) was isolated from a bacterium in a traditional Korean fermented medicinal herb preparation. The isolate, T2-16, was identified as Bacillus coagulans based on its 16S rRNA sequence and biochemical properties, and the strain was named Bacillus coagulans NRR-1207. When incubated in 10%(w/v) skim milk, Bacillus coagulans NRR1207 caused a decrease in the pH of the culture medium, as well as an increase in titratable acidity and viable cell counts. This strain also showed higher activities of ${\alpha}$-galactosidase, ${\beta}$-galactosidase, ${\alpha}$-glucosidase, naphthol-AS-BO-phosphohydrolase, and acid phosphatase when compared to other enzymes. It hydrolyzed oligomeric substrates, such as raffinose and stachyose, and liberated galactose, indicating that the Bacillus coagulans NRR1207 ${\alpha}$-galactosidase hydrolyzed the ${\alpha}$-1,6 glycoside linkage. These results suggest that the decreased stachyose and raffinose contents observed in fermented soy meal are due to this ${\alpha}$-galactosidase activity. Bacillus coagulans NRR1207 therefore has potential probiotic activity and could be utilized in feed manufacturing, as well as for hydrolyzing non-digestible soy meal components.

• Journal of Life Science
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• v.29 no.5
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• pp.545-554
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• 2019

The phytochemical compounds of Pueraria, a medicinally important leguminous plant, include various isoflavones that have weak estrogenic activity and a potential role in preventing chronic disease, cancer, osteoporosis, and postmenopausal syndrome. However, the major isoflavones are derivatives of puerarin and occur mainly as unabsorbable and biologically inactive glycosides. The bioavailability of the glucosides can be increased by hydrolysis of the sugar moiety using ${\beta}$-glucosidase. In this study, we investigated the antioxidant effects of a Pueraria extract after fermentation by Lactobacillus rhamnosus BHN-LAB 76. The L. rhamnosus BHN-LAB 76 strain was inoculated into Pueraria powder and fermented at $37^{\circ}C$ for 72 hr. The total polyphenol content of the Pueraria extract increased by about 134% and the total flavonoid content increased around 110% after fermentation with L. rhamnosus BHN-LAB 76 when compared to a non-fermented Pueraria extract. Superoxide dismutase-like activities, DPPH radical scavenging, and ABTS radical scavenging increased by approximately 213%, 190%, and 107%, respectively, in the fermented Pueraria extract compared to the non-fermented Pueraria extract. Fermentation of Pueraria extracts with L. rhamnosus BHN-LAB 76 is therefore possible and can effectively increase the antioxidant effects. These results can be applied to the development of improved foods and cosmetic materials.

• Food Science and Preservation
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• v.22 no.4
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• pp.535-544
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• 2015

This study was conducted to investigate the changes of isoflavone composition (glycoside and bio-active aglycone) in Cheonggukjang and to evaluate its quality characteristics depending on different soybean cultivars (Daewon, Daepoong, Wooram, Hwangkeumol and Saedanback). The bioactivity of Cheonggukjang was enhanced during fermentation at $37^{\circ}C$ for 48 h. Activities of ${\alpha}$-amylase, protease, and cellulase increased significantly after 48 h fermentation (p<0.05). In addition, amino-type nitrogen and reducing sugar contents in Cheonggukjang fermented with B. subtilis increased significantly after 48 h fermentation (p<0.05). Among the isoflavones, the content of $\beta$-glucosides and acetyl-glucosides decreased, while aglycone content increased during fermentation. Especially, Cheonggukjang fermented with Daepoong cultivars showed the greatest increase in daidzein, genistein and glycitein contents. After 48 h fermentation, the contents of daidzein, genistein and glycitein in the Cheonggukjang fermented with Daepoong cultivars increased significantly up to $503.65{\pm}2.76$, $111.40{\pm}0.42$, and $633.95{\pm}6.01{\mu}g/g$ (p<0.05), respectively. Total aerobic and anaerobic cell counts increased with increase in fermentation time. Therefore, it would be beneficial for the food industry if components of Cheonggukjang could be separated and used to develop functional products.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.1
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• pp.52-59
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• 2005

The study was targeted to saccharify foodwastes with the cellulolytic and amylolytic enzymes obtained from culture supernatant of Trichoderma harzianum FJ1 and analyze the kinetics of the saccharification in order to enlarge the utilization in industrial application. T. harzianum FJ1 highly produced various cellulolytic (filter paperase 0.9, carboxymethyl cellulase 22.0, ${\beta}$-glucosidase 1.2, Avicelase 0.4, xylanase 30.8, as U/mL-supernatant) and amylolytic (${alpha}$-amylase 5.6, ${\beta}$-amylase 3.1, glucoamylase 2.6, as U/mL-supernatant) enzymes. The $23{\sim}98\;g/L$ of reducing sugars were obtained under various experimental conditions by changing FPase to between $0.2{\sim}0.6\;U/mL$ and foodwastes between $5{\sim}20\%$ (w/v), with fixed conditions at $50^{\circ}C$, pH 5.0, and 100 rpm for 24 h. As the enzymatic hydrolysis of foodwastes were performed in a heterogeneous solid-liquid reaction system, it was significantly influenced by enzyme and substrate concentrations used, where the pH and temperature were fixed at their experimental optima of 5.0 and $50^{\circ}C$, respectively. An empirical model was employed to simplify the kinetics of the saccharification reaction. The reducing sugars concentration (X, g/L) in the saccharification reaction was expressed by a power curve ($X=K{\cdot}t^n$) for the reaction time (t), where the coefficient, K and n. were related to functions of the enzymes concentrations (E) and foodwastes concentrations (S), as follow: $K=10.894{\cdot}Ln(E{\cdot}S^2)-56.768,\;n=0.0608{\cdot}(E/S)^{-0.2130}$. The kinetic developed to analyze the effective saccharification of foodwastes composed of complex organic compounds could adequately explain the cases under various saccharification conditions. The kinetics results would be available for reducing sugars production processes, with the reducing sugars obtained at a lower cost can be used as carbon and energy sources in various fermentation industries.

• Journal of Microbiology and Biotechnology
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• v.22 no.3
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• pp.343-351
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• 2012

In this paper, the kinetics of a cloned special glucosidase, named ginsenosidase type III hydrolyzing 3-O-glucoside of multi-protopanaxadiol (PPD)-type ginsenosides, were investigated. The gene (bgpA) encoding this enzyme was cloned from a Terrabacter ginsenosidimutans strain and then expressed in E. coli cells. Ginsenosidase type III was able to hydrolyze 3-O-glucoside of multi-PPD-type ginsenosides. For instance, it was able to hydrolyze the 3-O-${\beta}$-D-(1${\rightarrow}$2)-glucopyranosyl of Rb1 to gypenoside XVII, and then to further hydrolyze the 3-O-${\beta}$-D-glucopyranosyl of gypenoside XVII to gypenoside LXXV. Similarly, the enzyme could hydrolyze the glucopyranosyls linked to the 3-O-position of Rb2, Rc, Rd, Rb3, and Rg3. With a larger enzyme reaction $K_m$ value, there was a slower enzyme reaction speed; and the larger the enzyme reaction $V_{max}$ value, the faster the enzyme reaction speed was. The $K_m$ values from small to large were 3.85 mM for Rc, 4.08 mM for Rb1, 8.85 mM for Rb3, 9.09 mM for Rb2, 9.70 mM for Rg3(S), 11.4 mM for Rd and 12.9 mM for F2; and $V_{max}$ value from large to small was 23.2 mM/h for Rc, 16.6 mM/h for Rb1, 14.6 mM/h for Rb3, 14.3 mM/h for Rb2, 1.81mM/h for Rg3(S), 1.40 mM/h for Rd, and 0.41 mM/h for F2. According to the $V_{max}$ and $K_m$ values of the ginsenosidase type III, the hydrolysis speed of these substrates by the enzyme was Rc>Rb1>Rb3>Rb2>Rg3(S)>Rd>F2 in order.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.41-48
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• 2000

A bacterial strain, designated as JK-43, producing extracellular cyclodextrin glucanotransferase (CGTase)[EC 2.4.1.19] was isolated from kimchi. The CGTase from isolated strain JK-43 showed the transglucosylation activity from soluble starch to L-ascorbic acid(AA) compared to those obtained from other strains. A main product formed by this reaction was identified as $2-O-{\alpha}-glucopyranosyl$ L-ascorbic acid(AA-2G) by testing its susceptibility to ${\alpha}-glucosidase$ hydrolysis, the HPLC profiles, and through the elementary analysis. the ${\beta}-CD,\;{\gamma}-CD$, potato starch and corn starch were identified to be suitable glucosyl donor for transglucosylation reaction on AA by CGTase. Acceptor specificity on AA-2G production was examined by use of AA, Iso-AA and AA-2P. Transglucosylation was observed toward AA-2P as well as AA and Iso-AA. The microorganism isolated from kimchi was identified as a strain of Bacillus sp. JK-43 based on the morphological, cultural, biochemical characteristics and partial 16SrDNA sequence analysis. The maximal CGTase production was observed in a medium containing 1.0% soluble starch, 1.0% yeast extract, 1.0% $Na_2CO_3\;0.1%\;K_2HPO_4,\;and\;0.02%\;MgSO_4{\cdot}7H_2O$ with initial pH 7.0. The strain was cultured at $37^{\circ}C$ for 26 hrs with reciprocal shaking.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.133-138
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• 2008

Fire can affect microbial community structure of soil through altered environmental conditions, nutrient availability, and biotic source for microbial re-colonization. We examined the influence of fire on chemical properties and soil enzyme activities of soil for 10 months. We also characterized the soil microbial community structure through ester-linked fatty acid analysis(EL-FAME). For this study, we established five burned plots(1*1 m) and 5 unburned plots outside the margin of fire. Soil was sampled three soil cores in a each plots and composited for analysis at 1, 3, 5, 8, and 10 month after fire. The fire caused an increase in soil pH, exchangeable Ca, and Mg, organic matter, available $P_2O_5$ compared to unburned sites. The content of $NH_4-N$ in burned site was significantly higher than that of unburned site and this effect continued for 8 months after fire. There was no difference of $NO_3-N$ content in soil between burned and unburned site. Fire caused no change in acid phosphatase and arylsulfatase activities but $\beta$-glucosidase and alkaline phosphatase activities in burned site were increased compared to unburned site. Microbial biomass as estimated by total concentration of EL-FAMEs in burned sites was significantly higher than that of unburned sites at one month after fire. Burned site decreased the EL-FAMEs indicative of gram-positive bacteria and tended to increase the fatty acid associated with gram-negative bacteria at one and three months after fire. The sum of EL-FAME compound $18:2{\omega}6,9c$ and $18:1{\omega}9c$ as served fungal biomarkers was decreased in burned site compared to unburned site.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.164-167
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• 2005

The culture condition and medium composition for the enhanced mycelial growth of Lepista nuda DGUM 26501 were investigated. The optimal temperature and pH for the mycelial growth were $24^{\circ}C$ and $7.0\~8.0$, respectively. The partial pressure of oxygen for the enhanced mycelial growth was more than $10\%\;O_2$. When Czapek-Dox medium was used as a minimal medium, manitol and xylitol were very good carbon sources. Organic nitrogen sources were better than inorganic ones for mycelial growth. As the nitrogen source tested, com steep liquor, soytone and protease peptone were the best as a source of organic nitrogen sources. When ammonium phosphate as phosphorus sources was used, the enhanced mycelial growth was shown. Nicotinic acid was proved to be the most appropriate source of vitamin. After the mycelia of L. nuda DGUM 26501 was cultivated at $24^{\circ}C$ for 10 days in LNM broth (pH 7.0), the activities of extracellular enzyme were determined. The specific activity of $\alpha-amylase$ was much higher than those of other enzymes. However, little or no enzyme activities of $\beta-glucosidase$, CMCase, laccase and lipase were found.