• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.272-279
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• 2003

To determine optimal fermentation period of wild vegetables mixed with black sugar without microorganisms during plant extract fermentation food processing, changes in chemical components, quality characteristics of the fermented broth, and physiological functionality during fermentation period were investigated. pH and $^{\circ}Bx$ of fermented broths decreased gradually during fermentation period. Except persimmon leaf, viscosity of fermented broths of wild vegetables decreased after 3 months fermentation period. Amylase activity increased to $167{\sim}800%$ of its initial level after 6 months fermentation period, and invertase activity decreased by $60{\sim}170$ units after 1 month fermentation. No significant level of cellulase activity was observed. In the sensory evaluation test, inherent flavors and tastes of the wild vegetable decreased during the fermentation period, while those of others gradually increased. Overall acceptability was the highest after 3 months fermentation. Content of total phenolic compounds and electron-donating ability were highest after 3 to 4 months fermentation period, and decreased thereafter. Except Mugwort, tyrosinase inhibitory activity was found in all fermented broths. SOD-like activities were $23.0{\sim}25.1$ and $27.0{\sim}29.2%$ in fermentation broths of acacia flower and persimmon leaf, respectively, and were maintained throughout the fermentation period. Based on these results, fermentation period of 3 to 4 months was determined to be appropriate for plant extract fermentation food processing.

• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.63-70
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• 1997

The extracts from Agastache rugosa O. Kuntze, their chloroform and hexane fractions, and estragole identified from hexane fraction were tested to investigate the effects on the growth and metabolic activities of several true fungi. The fungi used were: Aspergillus oryzae KFCC 890, Aspergillus niger KCCM 11240, Saccharomyces cerevisiae IAM 4597, Saccharomyces ellipsoideus PNU 2215. The growth of S. Cerevisiae by treatment of water extract(1%), hexane fraction (0.05%), and estragole (0.05%) were inhibited 93%, 50%, and 33% respectively, and S. ellipsoideus was also inhibited markedly with delaying the alg phase maximum 12 hrs. The growth of A. oryzae was inhibited by treatment of extracts and fractions. The echanol production by S. cerevisiae was increased more than two times in the highest value around 42 hrs incubation by water extract, but chloroform fraction inhibited its production. The glucoamylase actibities by A. niger were strongly inhibited by hexane and chloroform fractions (0.05%). The invertase activity by S. cerevisiae using estragole (0.05%) reached to 57.5% of control group. S. cerevisiae treated with the estragole was damaged the cell wall and cell membrane, leaked the protoplasm, and observed broken pieces of cell.

• Journal of Life Science
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• v.14 no.3
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• pp.429-434
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• 2004

Levansucrase gene (levU) from Zymomonas mobilis was subcloned downstream of GALl promoter in pYES 2.0 and pYInu-AT [GALl0 promoter＋exoinulinase signal sequence of Kluyveromyces marxianus], resulting pYES-levU and pYInu-levU, respectively. The two expression plasmids were introduced into an invertase-deficient strain, Saccharomyces cerevisiae SEY2102, and then transformants showing high activity of levansucrase were selected. When each yeast transformants was cultivated in medium containing galactose, the extracellular and intracellular activities of levansucrase reached about 7.17 U/㎖ with the strain harboring pYES-levU and 6.61 U/㎖ with the strain harboring pYInu-levU. It was found that about 50% of levansucrase were detected in the medium and periplasmic space, and exoinulinase signal sequence didn't enhance the secretion efficiency. Furthermore, the recombinant levansucrase expressed in yeast seems to be produced as a hyper-glycosylated form.

• Korean journal of applied entomology
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• v.10 no.1
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• pp.23-30
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• 1971

This work was carried out to study the chemical properties, the activity of several enzymes, chemical components and the respiratory intensity of mite galls on the leaves of Lycium chinense MILL. caused by Eriophyes kuke KISHIDA. The activities of catalase and peroxidase were higher in the gall tissue, when compared to the healthy tissue, and were increased as tile gall developed. The activity of phosphorylase of the healthy tissue seemed to be higher than that of the large gall l tissue, considering the competitive inhibition of phosphomonoeoterase and $\beta-amylase$, The activities of invertase and $\beta-amylase$ were about two times higher in the large sail tissue than those of the healthy tissue. The content of the crude protein was $20\%$ higher in the small gall tissue than that of the healthy leave tissue, and decreased as the gall matured. On the other hand, the reducing sugar level was less in the small gall tissue than that of the healthy leaves, but as the gall grew, the content of reducing sugar of the gall tissue was increased. The contents of phosphorus and tannin were increased gradually as the gall matured, and their content showed about two times higher than those of the healthy. The matured gall tissue showed higher $QO_2$ than the healthy tissue. On the other hand, the matured gall tissue presented lower $QCO_2$ than the healthy tissue, and the RQ of the healthy tissue was higher than that of the gall tissue.

• Microbiology and Biotechnology Letters
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• v.22 no.2
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• pp.152-157
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• 1994

Inulinase of Kluyveromyces marxianus origin was produced by recombinant yeast Saccharomyces cerevisiae under the control of GAL1 promoter, to examine the expression and localization of inulinase in a repressed(galactose-free) or derepressed(galactose-containinga) medium. The inulinase gene(INU1A) was constitutively expressed at 6.7 units/ml in a repressed medium. When the cell started to utilize galactose in a derepressed medium, the INU1A gene began to be expressed, and the final expression level reached about 45 units/ml. According to be the nondenaturingPAGE analysis, inulinase produced by S. cerevisiae was found to be less glycosylated than the bakers yeast invertase. In addition, its glycosylation pattern was less heterogeneous than the K. marxianus inulinase. The supplementation of inulin or raffinose into the derepressed medium increased the cell growth rate, while the expression of INU1A was repressed. Regardless of the carbon sources examined, most of inulinase activity (more than 98%) was found in the extracellular medium, indicating excellent secretion efficiency.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.428-434
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• 2001

A viscous substance producer strain BS62, which was isolated from conventional Chungkookjang, was examined for its productivity of levansucrase and levan during soybean fermentation at $37{\circ}C$. After one day of cultivation, the enzyme activity reached the highest level, 8 units $ml^{-1}$. Extracts of fermented soybeans were precipitated by ethanol and hydrolyzed by either 0.1 N HCl or invertase, and the hydrolyzates were analyzed using thin layer and ion chromatographies. Fructose was the only sugar detected. This suggest that fructose was derived from the levan produced by the strain BS62 during soybean fermentation. The aerobic, endospore-forming bacterium BS62 was identified as a Bacillus subtilis sp., based on the composition of its cellular fatty acids and phylogeny, which was determined by its 16S rDNA sequence.

• Preventive Nutrition and Food Science
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• v.3 no.2
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• pp.152-156
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• 1998

A Fructan-degrading enzyme was partially purified from onion (Allium cepa)bulbs by a combination of ammonium sufate precipitation, concanavalin-A-Affinity chromatography, and ion-exchange and gel-filtration chromatography. The enzyme hydrolyzed sucrose more effectively than inulin and was identified as a $\beta$- fructofuranosidase (invertase). The optimum pH and temperature were pH 5.5 and 35$^{\circ}C$, respectively. The enzymehydrolyzed sucrose with a Km of 1.2mM . The soluble $\beta$-fructofuranosidase is likely glycoprotein based on its ability to bind the lectin concanavalin-A. The enzyme was heatlabie, with mose activity being lost at 5$0^{\circ}C$ in 1 hr of incubation. The onion $\beta$-fructofuranosidase was partially inhibited by ZnCl2 HgCl2 and CuSo4.

• Microbiology and Biotechnology Letters
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• v.25 no.5
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• pp.448-453
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• 1997

Enzyme activities, production of killer toxin and some functionality of forty seven yeasts isolated from traditional Meju were investigated in culture broth and cell free extracts. Activities of $\alpha$-galactosidase, invertase and inulinase were detected in cell free extracts of 38 strains, 43 strains and 45 strains, respectively and acidic and neutral protease activities also were detected in culture broth of all the strains, $\beta$-Galactosidase activity was detected in cell free extracts of OE-20 and S-14 strains. Killer toxins were produced by OE-12, S-8 (Candida spp.), OE-19 (Zygosaccharomyces spp.) and S-3 (Saccharomyces spp.). Culture broth of OE-23 and S-9 showed 61.3% and 59.2% of antioxidant activity to $\alpha$, $\alpha$-diphenyl-$\beta$-picrylhydrazyl(DPPH), but nitrite-scavenging ability as well as inhibition of tyrosinase and polyphenol oxidase were not appeared in all the strains.

• KSBB Journal
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• v.8 no.4
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• pp.320-327
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• 1993

Latex microspheres of styrene/acryl copolymer with acrylamide functional group were used for the stable covalent immobilization of an enzyme applicable for enzymatic synthesis of glycoside. The latex microspheres were coated with polyethyleneimine to establish structural and functional properties relevant to the covalent Immobilization with a high retention of activity. Polythyleneimine-coated microspheres satisfactorily immobilized the invertase for methyl fructoside synthesis, and model reaction were formed into alginate-enclosed microspheres biocatalyst. Using the alginate-enclosed microspheres biocatalyst, the yield of model glycoside was obtained as high as 52.2% at concentration of aqueous 30%(v/v) methanol and 0.291mo1/1 sucrose solution with 2U/ml of activity. The present study showed that the latex microspheres were successfully applied to enzymatic synthesis of glycoside.

• The Korean Journal of Mycology
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• v.31 no.1
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• pp.28-33
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• 2003

To establish the optimal fermentation periods in the manufacture of mushroom fermentation foods using sugar, changes of quality characteristics of the mushrooms fermentation broth were investigated with changes of enzyme activity and physiological functionality during fermentation. Viscosity, L value (lightness), a value (redness) and b value (yellowness) were significantly decreased after 3 months of fermentation and after that, increased. In sensory evaluation test, unique flavors and tastes of mushrooms in the fermented broth were decreased during fermentation, whereas the other tastes and flavors were gradually increased. Overall acceptability was the highest in the 3 months of fermentation broth. ${\alpha}-Amylase$ activities of the fermented broth were significantly increased to 1 month of fermentation, however invertase and cellulose activities were low or not detected in the fermented broth. Antioxidant activities were the highest in 4 months of fermentation and after that, decreased. Tyrosinase inhibitory activities were high in all samples and they were not changed during fermentation. SOD-like activity was high in the fermentation broth of Flammulina velutipes and it was also not changed during fermentation. In conclusion, optimal fermentation periods in the manufacture of mushroom fermentation foods using sugar was 3 or 4 months.