• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.444-449
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• 1991

Synthesis of maltosyl-$\beta$-cyclodextrin using maltose ($G_2$) and $\beta$-cyclodextrin ($\beta$-CD) as substrates through the reverse reaction of pullulanase was investigated. The optimal conditions for the condensation reaction were as below: mixing ratio of maltose to $\beta$-CD of 12.7, mixed substrate concentration of 70% (w/w, 70 g/100 ml $H_2O$), and amount of pullulanse of 350 units/100 ml. The concentration of synthesized maltosyl-P-CD concentration was reached up to 2.31 g/100 rnl at above reaction conditions, which corresponded the conversion yield of 43% (w/w, g of branched-CD/g of CD). The synthesis of maltosyl-$\alpha >\gamma >\beta$-CD was also attempted, and conversion yield was in the order of a>y>J3-CDs. Condensation reaction between various maltooligosaccharides ($G-1\sim G_6$ showed that maltose was the most effective oligorner for condensation reaction with $\beta$-CD. To increase the conversion yield various alcohols were added into the reaction mixture, amyl alcohol was found to be the most acceptable alcohol for increasement of convesion yield which increased from 43.0 to 83.0% upon addition of same volume of amyl alcohol into the reaction mixture.

• Korean Journal of Food Science and Technology
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• v.11 no.4
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• pp.273-277
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• 1979

Free sugars in various ginseng products, Korean and Russian Acanthopanaxes were analyzed by gas liquid chromatography. Ginseng products included Korean red ginseng, white ginseng with skin produced in Korea, Canada, and America, and extracts of red and white ginseng. ${\alpha}-\;and\;{\beta}-fructoses,\;{\alpha}-\;and\;{\beta}-glucoses$, galactose, sucrose, and ${\alpha}-\;and\;{\beta}-maltoses$ were identified in Korean and American white ginsengs with skin, and in Korean red ginseng. However ${\alpha}-\;and\;{\beta}-maltoses$ were not detected in Canadian white ginseng with skin. Total amount of sugars identified in white ginseng with skin was higher than that in red ginseng. ${\alpha}-\;and\;{\beta}-fructoses,\;{\alpha}-\;and\;{\beta}-glucoses$, galactose, sucrose and ${\alpha}-\;and\;{\beta}-maltoses$ were identified in red and white ginseng extracts. Fructose was a major sugar in red ginseng extract while it was sucrose in white ginseng extract. ${\alpha}-\;and\;{\beta}-glucoses$, galactose, sucrose and ${\alpha}-\;and\;{\beta}-maltoses$ were identified in Russian Acanthopanax, and their patterns were similar to that of ginseng, while ${\beta}-fructose,\;{\alpha}-\;and\;{\beta}-glucoses$ and sucrose were identified in Korean Acantopanax and total amount of sugars was only one third of that in Russian Acanthopanax.

• Microbiology and Biotechnology Letters
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• v.45 no.4
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• pp.277-283
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• 2017

To produce sweet liquor without artificial sweeteners, 8 traditional rice pre-treatment methods (juk, beombeok, seolgitteok, gumeongtteok, mulsongpyeon, injeolmi, gaetteok, and godubap) were analyzed in this study. The formation of sugars with the help of ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase using nuruk as a substrate has been previously confirmed. During the early stages of the pre-treatment processes, the amount of maltose produced (in descending order of its concentration) by ${\alpha}$-amylase was observed to be as follows: gaetteok > seolgitteok > beombeok > mulsongpyeon > juk > injeolmi > gumeongtteok > godubap. However, changes in maltose concentrations with respect to the pre-treatment processes after 48 hours were observed to be as follows: injeolmi > beombeok = godubap > gumeongtteok > gaetteok = mulsongpyeon > seolgitteok > juk. Maltose produced using either ${\alpha}$-amylase or ${\beta}$-amylase showed similar results. Glucoamylase produced 10 mg/ml of glucose during the godubap process, which was the highest amount of glucose among all the methods. Moreover, when ${\alpha}$-amylase, ${\beta}$-amylase, and glucoamylase were used concurrently, glucoamylase increased glucose production in the later stages. Therefore, the possibility of producing sweet liquor without employing artificial sweeteners was confirmed, even if the amount of sugar in the liquor varied with the pre-treatment process.

• Microbiology and Biotechnology Letters
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• v.19 no.3
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• pp.290-295
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• 1991

Direct conversion of raw starch without liquefaction to maltose using maltose-forming fungal a-amylase (Fungamyl) was carried out in an agitated bead enzyme reactor (bioattritor). The reaction rate in bioattritor was comparable with conventional method which utilized liquefied soluble starch. Moreover the extent of maltose formation increased substantially compared with conventional method; from 150 g / I of raw starch, around 95 g/l of maltose was formed and 72% of maltose content in sugar mixture was achieved. Especially, pH influenced greatly not only on total sugar formation from raw starch in bioattritor but also on maltose content in sugar mixture. The optimal pH for maltose formation from raw starch was shifted into the weak alkaline pH, the optimal pH of 8.0~9.0 in bioattritor contrast to pH of 5.0~5.5 for liquefied starch. The maltose formation and content were also affected by the amounts of Fungamyl added and raw starch concentration. Consumption of maltose-forming Fungamyl can be substantially reduced by supplementary addition of starch liquefying a-amylase (Termamyl).

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.57-61
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• 1996

The $\beta$-glucosidase enzyme was purified from E. coli carrying Cellulomonas fimi $\beta$-glucosidase gene. SDS-PAGE and analytical gel filtration revealed that molecular weight of this enzyme was 56,000 dalton and consisted of a single polypeptide.Inhibition caused by heavy metals and activation by dithiothreitol suggest the existence of essential thiol group in the enzyme. The enzyme was not active on maltose (glucose $\alpha$-1,4-glucose) which has a $\alpha$-linkage, whereas it was active on lactose (glucose $\beta$-1,4-glucose), PNPG (p-nitrophenyl $\beta$-D-glucopyranoside) and PNPC (p-nitrophenyl $\beta$-D-cellobioside), although its reaction rates were different.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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• pp.283-289
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• 1994

The production of maltose utilizing swollen extrusion starch seems to have many technical advantages, such as, high reaction rate and high yield, production of high purity concentrated maltose, and low energy consumption, over the conventional method utilizing liquefied starch. The characteristics of maltose formation in heterogeneous enzyme reaction system comtaining swollen extrusion starch was investigated using fungal $\alpha $-amylase. The influence of extrusion conditions on structure of extruded starch, such as, degree of gelatinization, water absorption index, and water solubility index was analyzed. The relationship between the structural features and maltose forming reaction was investigated, and the result was analyzed in terms of surface reaction of insoluble extruded swollen starch. The characteristics of maltose formation from swollen sxtrusion starch was compared using endo-type fungal $\alpha $-amylase and exo-type $\beta $anylase, and the structural trasformation of extruded starch was also observed to clarify the reaction mechanism.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.422-429
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• 1992

The effect of various water-activity depressors, such as pol yo Is, sugars, and polymers, on the conversion yields of the enzymatic synthesis of maltosyl-$\beta$-cyclodextrin from $\beta$-cyc1odextrin and maltose through reverse reaction of pullulanase was investigated. PEG 6000 of concentration of 10% (w/w) was found to be the most acceptable water-activity depressor resulting for increment of conversion yield from 43.0% to 55.9%, corresponding maltosyl-$\beta$-cyc1odextrin concentration of 3.02 g/100 ml H20. Water activity was changed from initial 0.966 to 0.914 upon addition of 20% (w/w) of PEG 6000. The conversion yields were inversely proportional to the water activities, and the increased conversion yield was caused by water activity depression which inhibited the hydrolysis reaction of maltosyl-$\beta$-CD to maltose and $\beta$-cyc1odextrin. The changes of enthalpy ($\Delta$H), entropy ($\Delta$S), and Gibbs free energy ($\Delta$G) were calculated to be 36.788 kJ/mole, 0.067 kJ/mole K. and 14.433 kJ/mole, respectively. The synthesis of maltosyl-$\beta$-CD could be increased substantially by the intermittent feeding of $\beta$-cyclodextrin. PEG 6000 could be separated effectively from reaction mixture using ultrafiltration membrane for reutilization.

• Biomolecules & Therapeutics
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• v.6 no.3
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• pp.242-246
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• 1998

The inhibitory activities of Amberlite active fraction, which was obtained from methanol soluble fraction of freeze dried slikworm urine, on the rat intestinal glycosidase-catalyzed enzymatic reaction were examined in in viro and in vivo experiments. Amberlite active fraction showed significant inhibitory effects on the hydrolysis of o-glycosidic bond, especially $\alpha$-1,4 bond. On the other hand, the inhibition on the hydrolysis of $\beta$-glycosidic bond was very weak. Oral administration of Amberlite active fraction resulted in a dose-dependent decrease in the blood glucose after an oral maltose load, and postprandial hyperglycemia in carbohydrate-loaded mice was suppressed by Amberlite active fraction at 60 mgHg in decreasing order of maltose, starch, sucrose and lactose. 60 mg/kg of Amberlite active fraction lowered the blood glucose level markedly after 18, 35, and 60 min after an oral maltose load and the antihyperglycemic activity was maintained upto 90 min. In alloxan-induced hyperglycemic mice, Amberlite active fraction at a dose of 100 mg/kg also significantly lowered blood glucose after an oral maltose load, and its efficacy was almost equivalent to that of acarbowe.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.445-447
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• 2018

Leuconostoc lactis CCK940, which was isolated from kimchi obtained from a Korean traditional market, produced an oligosaccharide with a degree of polymerization of more than 4. In this study, the draft genome sequence of L. lactis CCK940 was reported by using PacBio 20 kb platform. The genome of this strain was sequenced and the genome assembly revealed 2 contigs. The genome was 1,741,511 base pairs in size with a G + C content of 43.33%, containing 1,698 coding sequences, 12 rRNA genes, and 68 tRNA genes. L. lactis CCK940 contained genes encoding glycosyltransferase, sucrose phosphorylase, maltose phosphorylase, and ${\beta}$-galactosidase which could synthesize oligosaccharide.

• Journal of Life Science
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• v.11 no.2
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• pp.92-93
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• 2001

Bacillus sp. KYJ 963, which was isolated from Korean salt-fermented anchovy (anchovy-jeot), produces an extracellular ${\beta}$-amylase. The analysis of the digestion products of substrates by thin layer chromatography from the purified protein revealed that the enzyme could not hydrolyze maltose or ${\alpha}$-cyclodextrin. In the amino acid composition analysis, the major characteristic of the ${\beta}$-amylase was the high proportion of amino acids that possess short side chain such as glycine and alanine.