• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.902-908
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• 2018

Optimization of the culture medium to maximize menaquinone-7 (MK-7) production by Bacillus subtilis strain KCTC 12392BP in static culture was carried out using statistical experimental methods, including one factor at a time, fractional factorial design, and response surface methodology (RSM). Maltose (carbon source), tryptone (nitrogen source), and glycerol (activator) were identified as the key medium components for MK-7 synthesis by the fractional factorial design, and were selected for statistical optimization by RSM. The statistical analysis indicated that, in the range that was studied, maltose, tryptone, and glycerol were all critical factors having profound effects on the production of MK-7, with their coefficients for linear and quadratic all significant at the p < 0.05 level. The established model was efficient and feasible, with a determination coefficient ($R^2$) of 0.9419. The predicted concentrations of maltose, tryptone, and glycerol in the optimal medium were determined as 36.78, 62.76, and 58.90 g/l, respectively. In this optimized medium, the maximum yield of MK-7 reached a remarkably high level of $71.95{\pm}1.00{\mu}g/ml$ after 9 days of static fermentation, which further verified the practicability of this optimized strategy.

• Journal of Ginseng Research
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• v.28 no.3
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• pp.136-142
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• 2004

During our investigations on the relationship between the browning reaction of ginseng root and two compounds (arginyl-fructosyl-glucose and arginyl-fructose) in the model system of steaming and heat-drying processes for the preparation of red ginseng, the preheating treatment of main roots of raw ginseng at 60∼70$^{\circ}C$ prior to the steaming and heat-drying processes was found to bring about the gelatinization of starch granules. The enzymatic hydrolysis of gelatinized starch to maltose, a marked formation of maltose, and the increase of both free arginine and total amino acids, resulting the acceleration of the Maillard type-browning reaction of ginseng root during the steaming and heat-drying processes, and the rise of brown color intensity of red ginseng. These results show that the preheating treatment may be effective for the decrease of inside white of red ginseng.

• Preventive Nutrition and Food Science
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• v.12 no.1
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• pp.51-57
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• 2007

The effects of maesil extract addition on the palatability and quality of kochujang, a traditional Korean condiment, were investigated in terms of the microbial characteristics, enzyme activities, and taste components during 100 days of fermentation. Viable cell counts of bacteria and yeast in maesil extract-added kochujang (maesil kochujang) were increased in proportion to added maesil extract from 1 to 5% during fermentation, up to 80 and 20 days, respectively and maintained $5.0{\sim}14.5{\times}10^6$ CFU/g. Activities of α-amylase, $\beta$-amylase, and protease were also increased in proportion to added maesil extract up to 20, 20, and 60 days, respectively and were higher than those of control during the aging process. The major organic acids in maesil kochujang were citric and malic acid. Composition and content of free sugar were not changed remarkably in general by the addition of maesil extract except maltose. The major free sugars of maesil kochujang were in the order of glucose>sucrose>maltose, and glucose content decreased significantly as the ratio of maesil extract increased, while maltose content increased significantly (p<0.05).

• Journal of Life Science
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• v.10 no.2
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• pp.125-130
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• 2000

To overproduce endoxylanase from a recombinant Bacillus subtilis harboring the pJHKJ4 plasmid, the effects of carbon and nitrogen sources on the cell growth and expression level of endoxylanase were investigated in the flask cultures. Among the various carbon and nitrogen sources tested, glucose and maltose as carbon source and yeast extract as nitrogen source were found to be the most effective for the cell growth and the endoxylanase expression. When the concentration of glucose was increased from 0.5% to 5%, the highest activity of extracellular endoxylanse, 166 unit/$m\ell$, was observed at 2% glucose. In case of maltose, the endoxylanase was stably produced at the level of 180 unit/$m\ell$, regardless of the concentration of maltose. The higher the concentration of yeast extract, the greater cell growth and endoxylanase expression were obtained. However, the highest endoxylanase activity per unit cell mass was observed with 1% yeast extract. With the optimized medium (2% glucose, 1% yeast extract, etc), about 630 unit/$m\ell$ of endoxylanse was expressed through the batch fermentation in a fermentor, which expression level corresponded to about 0.7 g-endoxylanase protein /$\ell$. It was also found that the plasmid was stably maintained above 70% level, and more than 90% of endoxylanase activity was detected in the extracellular medium.

• KSBB Journal
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• v.16 no.2
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• pp.200-206
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• 2001

In this study we tried to optimize the enzyme reaction conditions for the synthesis of highly branched isomaltodextrin (Mw > 2.5 kDa) using two dextransucrases from L. mesenteroides B-742CB and B-512FMCM that are dextransucrase constitutive mutants. As the concentration of sucrose or the ratio of maltose to sucrose increased, the amount of dextran decreased and the number and the amount of acceptor-products (of sucrose or maltose) increased. With high sucrose concentration (over 34%), there was more branched isomaltodextrin (as acceptor products) than dextran. When the ratio of sucrose to maltose was 2.5, there produced 86.7% of isomaltodextrin were produced. The Mw of dextrans, however, was over 2${\times}$10(sup)6 and there was no significant amounts of branched clinical dextran or high molecular weight oligosaccharides. With the combined activities of B-742CB dextransucrase and B-512FMCM dextransucrase we could synthesize high molecular weight branched isomaltodextrin (Mw>2.5 kDa). The high molecular weight dextran was composed of high branches as B-742CB dextran.

• Korean Journal of Pharmacognosy
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• v.52 no.4
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• pp.212-218
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• 2021

Fatsia japonica is grown wild to Eastern Asia, including Korea, Japan, and Taiwan and it is known as ornamental plant, and it is also known that pharmacological action. In this study, we have selected the stem of F. japonica with consideration about biological activities and amount of yield. In addition, four compounds (1-4) were isolated from the stem of F. japonica. Extensive spectroscopic and chemical studies established the structures of these compounds as maltose (1), begoniifolide A (2), leiyemudanoside B (3), leonticin F (4). All of the compounds were investigated for their anti-inflammatory, anti-neuroinflammatory, and neuro-protective effects on RAW264.7, BV2, and HT22 cells. However, among four compounds, there were no effects by maltose (1), begoniifolide A (2), leiyemudanoside B (3), leonticin F (4) on the anti-inflammatory, anti-neuroinflammatory, and neuro-protective action. This is the first report on the isolation of maltose (1), begoniifolide A (2), leiyemudanoside B (3), leonticin F (4) from the stem of F. japonica. Begoniifolide A (2), leiyemudanoside B (3), leonticin F (4) were isolated for the first time from this plant. It might be necessary to continue the further studies to find the biological active compounds isolated from the stem of F. japonica.

• 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.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.363-369
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• 2016

A putative cyclomaltodextrinase gene (licd) was found from the genome of Listeria innocua ATCC 33090. The licd gene is located in the gene cluster involved in maltose/maltodextrin utilization, which consists of various genes encoding maltose phosphorylase and sugar ABC transporters. The structural gene encodes 591 amino acids with a predicted molecular mass of 68.6 kDa, which shares less than 58% of amino acid sequence identity with other known CDase family enzymes. The licd gene was cloned, and the dimeric enzyme with C-terminal six-histidines was successfully produced and purified from recombinant Escherichia coli. The enzyme showed the highest activity at pH 7.0 and 37℃. licd could hydrolyze β-cyclodextrin, starch, and maltotriose to mainly maltose, and it cleaved pullulan to panose. It could also catalyze the hydrolysis of acarbose to glucose and acarviosine-glucose. In particular, it showed significantly higher activity towards β-cyclodextrin and maltotriose than towards starch and acarbose. licd also showed transglycosylation activity, producing α-(1,6)- and/or α-(1,3)-linked transfer products from the acarbose donor and α-methyl glucopyranoside acceptor.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.657-662
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• 1997

An attempt was made to investigate the chemical compositions of green pumpkin, edible flesh and seed of ripened pumpkin (Cucurbita moschata Duch.). The proximate compositions were moisture 9.34%, 11.98%, protein 12.70%, 13.38%, lipid 11.31%, 0.85%, carbohydrate 64.32%, 62.18%, fiber 6.31%, 4.54% and ash 6.05%, 7.76% in green and ripened pumpkin, respectively. The compositions of free sugar were glucose, fructose, sucrose, lactose and maltose in green and ripened pumpkin, respectively. During flesh growth, glucose, maltose and lactose was increased but sucrose and fructose was decreased in pumpkin. Pattern of 15 amino acid compositions in green and ripened pumpkin was shown to be of similarity. Major amino acids were glutamic acid, aspartic acid and alanine in green pumpkin and edible flesh of ripened pumpkin. And major amino acid in seed of ripened pumpkin were glutamic acid, arginine, aspartic acid and leucine. The predominant fatty acids were palmitic acid, linolenic acid, linoleic acid and oleic acid in green and ripened pumpkin, respectively. And those in seed of ripened pumpkin were linoleic acid, palmitic acid and oleic acid. The richest mineral contained in the green and ripened pumpkin was shown to be K and followed by Ca, Mg, Na and Fe in order.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.716-721
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• 1997

In order to improve the quality of sikhe, Korean traditional sweat rice drink, wheat malt, covered barley malt and naked barley malt were used to prepare sikhe. The optimum temperature of amylase was $60^{\circ}C$ in malt extract. After heat treatment of amylase for 2 hr at $70^{\circ}C$, residual activity of amylase was less than 20% in malt extract. Amylase activity during sikhe preparation was decreased gradually. The sikhe saccharifyed for 6 hr had $6250{\sim}25029$ units of amylase acitivity. The contents of glucose, maltose and maltotriose were increased with increasing time. Maltose content was the highest, followed by glucose and maltotriose. The pH and titrable acidity were slightly changed. The sweetness of sikhe prepared with wheat was 11.3%, and others were 11.1% and 10.4%. The sikhe prepared with naked barley was evaluated the most palatable sikhe.