• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.430-437
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• 1993

This study was carried out for high quality mirin Production by fusant F-50. Cellularly fused between Aspergillus oryzae 9-12 and Aspergillus shirousamii 6082-60. The conventional and the improvement methods in Mirin-making by F-50 showed high level of total sugar, reducing sugar and amino-nitrogen of 42%, 38% and 0.18%, respectively. Free amino acids in Mirin were found to 387.2 mg% glutamic acid, 283.8 mg% arginine, 244.0 mg% leucine, 218.0 mg% aspartic acid, 231.1 mg% alanine, 168.3 mg% serine and 148 mg% phenylalanine. Organic acids in Mirin were contained: oxalic acid, citric acid, malic acid, succinic acid, lactic acid, acetic acid and propionic acid. Sugars such as glucose, maltose, isomaltose, maltotriose, ribose, isomaltotriose and isomatotertraose were also found in Mirin. The clouding formation of Mirin made by F-50 showed 0.03 alcohol clouding, 0.08 water clouding and negative heat clouding.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.724-731
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• 1990

The fermentation process of Andong Sickhae including optimal composition of the product was investigated. Through sensory evaluation and ingredient analysis of ten samples prepared in the laboratory and the samples collected from Andong region, we found that the ratio of ingredient of the product by weigh are as follow : [glutinous rice(80) : malt(50) : radish(100) : water(500) : ginger(8) : red pepper(4)]. The level of nitrogen compound turned out to be low while that of soluble protein and salt soluble protein was high. The content of total sugar and reducing sugar was found to be considerable high and among the free sugar, maltose was the highest(80%), followed by glucose and maltotriose. Activities of acid protease and saccharogenic amylase were 1.55 unit per milliliter and $12.5D^{40}_{30}^{\circ}$ respectively. Results of sensory evaluation showed that the good Andong Sickhae turned out to have well harmonized taste of flavor, sweetness and sourness while the color looked slightly red.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.2
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• pp.106-111
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• 2003

A novel carbohydrolase, which is a DXAMase, containing both dextranase and amylase equivalent activities, was purified from Lipomyces starkeyi KSM22. The purified DXAMase was also found to hydrolyze cellobiose, gentiobiose, trehalose and melezitose, while disproportionation reactions were exhibited with various di- and tri-saccharides, such as maltose, isomaltose, gentiobiose, kojibiose, sophorose, panose, maltotriose, and isomaltotriose with various kinds of oligosaccharides produced as acceptor reaction products. Furthermore, the purified DXAMase hydrolyzed raw waxy rice Starch and produced maltodextrin to the extent of 50% as a glucose equivalent.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.251-254
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• 2000

Effect of carbon sources including agro-industrial byproduct on cell growth and production of curdlan by Agrobacterium sp. ATCC 31749 was investigated. Maximal production of curdlan was obtained when the carbon source was sucrose. The conversion rate of curdlan from 2% (w/v) sucrose was 59%. Glucose, mannose and maltose were also found to be good carbon sources for production of curdlan. Production of curdlan increased up to 3% (w/v) glucose as the carbon source and then decrease as the concentration of glucose increased. The major components of agro-industrial byproduct (AIB) were glucose, maltose, and maltose, and maltotriose. Agrobacterium sp.ATCC 31749 utilized up to 25% (v/v) AIB and produced curdlan with 29.8g/1.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1544-1549
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• 2008

MhMTS and MhMTH are trehalose ($\alpha$-D-glucopyranosyl-[1,1]-$\alpha$-D-glucopyranose) biosynthesis genes of the thermophilic microorganism Metallosphaera hakonensis, and encode a maltooligosyltrehalose synthase (MhMTS) and a maltooligosyltrehalose trehalohydrolase (MhMTH), respectively. In this study, the two genes were fused in-frame in a recombinant DNA, and expressed in Escherichia coli to produce a bifunctional fusion enzyme, MhMTSH. Similar to the two-step reactions with MhMTS and MhMTH, the fusion enzyme catalyzed the sequential reactions on maltopentaose, maltotriosyltrehalose formation, and following hydrolysis, producing trehalose and maltotriose. Optimum conditions for the fusion enzyme-catalyzed trehalose synthesis were around $70^{\circ}C$ and pH 5.0-6.0. The MhMTSH fusion enzyme exhibited a high degree of thermostability, retaining 80% of the activity when pre-incubated at $70^{\circ}C$ for 48 h. The stability was gradually abolished by incubating the fusion enzyme at above $80^{\circ}C$. The MhMTSH fusion enzyme was active on various sizes of maltooligosaccharides, extending its substrate specificity to soluble starch, the most abundant natural source of trehalose production.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.109-114
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• 1997

The Oomycete Saprolegnia ferax produces an extracellular $\beta$-amylase, Maximum enzyme yield was attained after 7 days of growth in YNB starch medium (pH 6.5) at 25$\circ$C. The amylase was pu- rified 24-fold by ultrafitration, HPLC DEAE column and HPLC gel filtration. The purfied enzyme was a monomeric glycoprotein with a molecular weight of about 44,000 dalton. The pH and temperature optima were 6.5 and 50$\circ$C, respectively. The enzyme was fairly stable up to 50$\circ$C and at acidic pH region (pH 4.0-7.0). The apparent Km and Vmax values of the enzyme against soluble starch were 0.77 mg/ml and 2,174 $\mu$moles/mg protein, respectively. Amino acid analysis indicated that the enzyme was enriched in alanine, glycine, leucine and acidic amino acid. Starch hydrolysis with the enzyme released maltose but not glucose, whereas maltotriose, Schardinger dextrin ($\alpha$-cyclodextrin) and pullulan were not hydrolysed by the enzyme. The enzyme was inhibited by Schardinger dextrin, p-chloromercuribenzoate(PCMB), CU$^{2+}$' and Hg$^{2+}$. Inhibition of the enzyme by PCMB could be reversed by the addition of cysteine and mercaptoethanol.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.815-818
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• 2003

Maltosyl(G2)-erythritol, produced by the transglycosylation reaction of erythritol with maltotriose by Bacillus stearothermophilus maltogenic amylase, was not utilized either as a substrate for lactic acid production or for water-insoluble glucan synthesis. An inhibition assay of dextransucrase and mutansucrase showed that the dental caries suppression effect of G2-erythritol was greater than that of erythritol.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.73-79
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• 1994

The optimum cultural temperature and time for the pullulanase production by Bacillus cereus subsp. mycoides were 35$\circ $C and 48 hrs, respectively. The addition of egg albumin and casein to the basal medium increased the enzyme production. The enzyme was purified by ammonium sulfate fractionation and DEAE-cellulose column chromatography. specific activity of the purified enzyme was 82.37 U/mg protein and yield of theenzyume activity was 62.1%. The purified enzuyme showed a single band on ployacrylamide disc gel electrophoresis and its molecular weight was estimated to be 66.,000 by SDS-polyacrylamide disc gel electrophoresis. The isoelcular point for the purified enzyme was pH 5.0. The optimum temperature and pH were 50$\circ $C and pH 6.5, respectively. The purified enzyme was stable below 40$\circ $C and in the pH range of 6.5~10.0 The pullulanase activity was greatly inhited by Ag$^{+}$, Hg$^{2+}$ and EDTA, and its heat stability was increased by the addition of Ca$^{2+}$. The tydrolysis product with the enzyme on pullulan was maltotriose.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.352-355
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• 2000

Production of pullulan by Aureobasidium pullulans HP-2001 with agro-industrial byproducts was investigated. Agro-industrial byproducts from the rice processing industry for the traditional Korean food (AIB-A), apple juice production (AIB-B), and soybean sauce production (AIB-C) were used for carbon and nitrogen source for production of pullulan. Major components of AIB-A were glucose, maltose, maltotriose, and dextran. AIB-A and B were found to be good substitute to glucose as carbon source. Productivity of pullulan with AIB-A and B as carbon source was similar to that glucose. Molecular weight of pullulan produced with AIB-A and B was higher than that with glucose. Major components of AIB-B and C were carbohydrate, protein, fat and ash. AIB-C was also a good substitute to yeast extract as nitrogen source. Some of physiological conditions were examined for the large scale production of pullulan.

• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.309-313
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• 1997

Bench scale Sikhyes were produced from rice and glutinous rice and limit dextrins in rice Sikhye and glutinous rice Sikhye were purified by ethanol precipitation and Biogel P-2 gel chromatography and FPLC on Superose 12 column and analyzed. The purified limit dextrin in rice Sikhye and glutinous rice Sikhye showed bot signal of $\alpha$-1,4- and $\alpha$-1,6-glucosidic linkage with its estimation ratio of 4.5:1 and 5.9:1, respectively, by 1H-NMR analysis. Limit dextrins were hydrolyzed by pullulanase. The enzyme hydrolysis products contained maltose, maltotriose, maltotetraose, maltopentaose and matohexaose. These results suggest that limit dextrins were composed of these maltoolgosaccharide series with $\alpha$-1,6-glucosidic bond.