• Journal of Ginseng Research
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• v.24 no.1
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• pp.41-45
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• 2000

Maltooligosaccharides were produced from ginseng starch by hydrolysis of $\alpha$-amylase. And it was investigated that physicochemical properties and intestinal bacteria growing effort of maltooligosaccharides. The optimum level of the ginseng maltooligosaccharides was produced when 10% ginseng starch was hydrolyzed with 50 unit of Amano A $\alpha$-amylase per gram starch at 85。C for 24h. Viscosity and water holding capacity of the ginseng maltooligosaccharides were 37.7 cps at 20。C and 110.1% at 75% relative humidity, respectively. The ginseng maltooligosaccharides enhanced the growth of Bifidobaterium infantis.

• Food Science and Preservation
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• v.15 no.1
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• pp.99-104
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• 2008

To utilize non-heat treated alcoholic by-products of brown rice (Goami) as food sources, the quality characteristics changes according to the treatment conditions of cellulase were evaluated. Results showed that the increase of hydrolysis temperature correspondingly increased the soluble solids and total sugar amounts in the by-products of Goami, and total dietary fiber amount was found to be around 0.67% Reducing sugar concentration was the highest at the hydrolysis temperature of $70^{\circ}C$. Maltooligosaccharides amounts were detected to be the highest at the hydrolysis temperature of $80^{\circ}C$ and were also, maltopentose and maltopentose were found. In the soluble solid, total dietary fiber, reducing sugar and total sugar according to the cellulase concentration, the content of hydrolysates with enzyme were higher than control, and the content of hydrolysates with enzyme was similar (6.30 and 0.69% 3,600 and 5,500 mg% respectively). The content of maltooligosaccharides was increased with the increase of enzyme concentration, and the content was similar at more than 0.6%(w/w) of enzyme concentration. The soluble solids and total dietary fiber by hydrolysis time were found to be 6.25% and 0.70%, respectively at more than 60 min. of hydrolysis. The content of reducing sugar, total sugar and maltooligosaccharides were increased with the increase of hydrolysis time, and the content was similar at more than 120min. of hydrolysis (3,800, 5,680 and 1,950 mg% respectively). Based upon these results, the byproducts of Goami are expected to be valuable as various food sources showing the highest dietary fiber and maltooligosaccharides contents by the hydrolysis at $80^{\circ}C$ for 120 min. with the addition of 0.6%(w/w) of cellulase.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.457-464
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• 2008

An extracellular enzyme (RMEBE) possessing ${\alpha}-(1{\rightarrow}4)-(1{\rightarrow}6)$-transferring activity was purified to homogeneity from Rhodothermus marin us by combination of ammonium sulfate precipitation, Q-Sepharose ion-exchange, and Superdex-200 gel filtration chromatographies, and preparative native polyacrylamide gel electrophoresis. The purified enzyme had an optimum pH of 6.0 and was highly thermostable with a maximal activity at $80^{\circ}C$. Its half-life was determined to be 73.7 and 16.7 min at 80 and $85^{\circ}C$, respectively. The enzyme was also halophilic and highly halotolerant up to about 2M NaCl, with a maximal activity at 0.5M. The substrate specificity of RMEBE suggested that it possesses partial characteristics of both glucan branching enzyme and neopullulanase. RMEBE clearly produced branched glucans from amylose, with partial ${\alpha}-(1{\rightarrow}4)$-hydrolysis of amylose and starch. At the same time, it hydrolyzed pullulan partly to panose, and exhibited ${\alpha}-(1{\rightarrow}4)-(1{\rightarrow}6)$-transferase activity for small maltooligosaccharides, producing disproportionated ${\alpha}-(1{\rightarrow}6)$-branched maltooligosaccharides. The enzyme preferred maltopentaose and maltohexaose to smaller maltooligosaccharides for production of longer branched products. Thus, the results suggest that RMEBE might be applied for production of branched oligosaccharides from small maltodextrins at high temperature or even at high salinity.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.181-186
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• 1970

1) Conditions for the hydrolysis of starch by bacterial liquefying amylase (BLA), saccharifying amylase (BSA) and isoamylase were investigated. Out of four syrups prepared by different combinations of these enzymes, those made by BLA followed by BSA and/or isoamylase were comparable to sucrose syrup in canning of orange segments. 2) Two branched maltooligosaccharides were isolated from the hydrolyzate of starch by BLA and BSA, and their structures were tentatively identified as pentaose and hexaose having an ${\alpha}-1$, 6-linkage at the branching point.

• Journal of Microbiology and Biotechnology
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• v.19 no.12
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• pp.1547-1556
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• 2009

A novel thermostable $\alpha$-glucosidase (TtGluA) from Thermoanaerobacter tengcongensis MB4 was successfully expressed in E. coli and characterized. The TtgluA gene contained 2,253 bp, which encodes 750 amino acids. The native TtGluA was a trimer with monomer molecular mass of 89 kDa shown by SDS-PAGE. The purified recombinant enzyme showed hydrolytic activity on maltooligosaccharides, p-nitrophenyl-$\alpha$-D-glucopyranide, and dextrin with an exotype cleavage manner. TtGluA showed preference for short-chain maltooligosaccharides and the highest specific activity for maltose of 3.26 units/mg. Maximal activity was observed at $60^{\circ}C$ and pH 5.5. The half-life was 2 h at $60^{\circ}C$. The enzyme showed good tolerance to urea and SDS but was inhibited by Tris. When maltose with the concentration over 50 mM was used as substrate, TtGluA was also capable of catalyzing transglycosylation to produce $\alpha$-1,4-linked maltotriose and $\alpha$-1,6-linked isomaltooligosaccharides. More importantly, TtGluA showed exclusive regiospecificity with high yield to produce $\alpha$-1,6-linked isomaltooligosaccharides when the reaction time extended to more than 10 h.

• Journal of Microbiology and Biotechnology
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• v.18 no.4
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• pp.730-734
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• 2008

Barley ${\alpha}$-amylase genes, amy1 and amy2, were separately cloned into the expression vector of $pPICZ{\alpha}A$ and recombinant Pichia strains were established by homologous recombination. Both AMYs from Pichia shared almost identical hydrolysis patterns on short maltooligosaccharides to result in glucose, maltose, or maltotriose. Against insoluble blue starch, AMY1 showed the highest activity at 0.1-5 mM calcium concentration, whereas 15-20 mM was optimal for AMY2. On the hydrolysis of soluble starch, unexpectedly, there was no significant difference between AMYs with increase of calcium. However, the relative activity on various starch substrates was significantly different between AMYs, which supports that the isozymes are clearly distinguished from each other on the basis of their unique preferences for substrates.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.570-573
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• 2009

The debranching enzyme of Nostoc punctiforme (NPDE) is a novel enzyme that catalyzes the hydrolysis of $\alpha$-1,6-glycosidic linkages in starch, followed by the sequential hydrolysis of $\alpha$-1,4-glycosidic linkages. The debranching activity of NPDE is highly specific for branched chains with a degree of polymerization (DP)>8. Moreover, the rate of hydrolysis of $\alpha$-1,4-linkages by NPDE is greatly enhanced for maltooligosaccharides (MOs) with a DP>8. An analysis of reaction mixtures containing various starches revealed the accumulation of maltooctaose (G8) with glucose and maltose. Based on the novel enzymatic properties of NPDE, an MO mixture containing more than 60% G8 with yield of 18 g G8 for 100 g starch was prepared by the reaction of NPDE with soluble starch, followed by ethanol precipitation and gel permeation chromatography (GPC). The yield of the G8-rich mixture was significantly improved by the addition of isoamylase. In summary, a 4-step process for the production of a G8-rich mixture was developed involving the enzymatic hydrolysis of starch by NPDE.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1521-1526
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• 2007

A maltogenic amylase gene from Lactobacillus gasseri ATCC33323 (LGMA) was expressed in Lactococcus lactis MG1363 using the P170 expression system. The successful production of recombinant LGMA (rLGMA) was confirmed by the catalytic activity of the enzyme in liquid and solid media. The N-terminal amino acid sequencing analysis of the rLGMA showed that it was Met-Gln-Leu-Ala-Ala-Leu-, which was the same as that of genuine protein, meaning the signal peptide was efficiently cleaved during secretion to the extracellular milieu. The optimal reaction temperature and pH of rLGMA ($55^{\circ}C$ and pH 5, respectively) and enzymatic hydrolysis patterns on various substrates (${\beta}$-cyclodextrin, starch, and pullulan) supported that rLGMA was not only efficiently secreted from the Lactococcus lactis MG1363 but was also functionally active. Finally, the branched maltooligosaccharides were effectively produced from liquefied com starch, by using rLGMA secreted from Lactococcus lactis, with a yield of 53.1%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1388-1393
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• 2014

To enzymatically prepare amylopectin cluster (APC), cyclodextrin glucanotransferase (CGTase I-5) and its mutant enzyme from alkalophilic Bacillus sp. I-5 were employed, after which the hydrolysis patterns of CGTase wild-type and its mutant enzyme toward amylopectin were investigated using multi-angle laser light scattering. CGTase wild-type dramatically reduced the molecular weight of waxy rice starch at the initial reaction, whereas the mutant enzyme degraded waxy rice starch relatively slowly. Based on the results, the molecular weight of one cluster of amylopectin could be about $10^4{\sim}10^5g/mol$. To determine production of cyclic glucans from amylopectin, matrix-assisted laser desorption ionization time-of-flight mass spectrometry was performed. CGTase I-5 produced various types of cyclic maltooligosaccharides from amylopectin, whereas the mutant enzyme hardly produced any.

• The Korean Journal of Food And Nutrition
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• v.10 no.1
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• pp.92-96
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• 1997

A Korean commercial sweet rice drink "Sikhye" showed sucrose, fructose, glucose, maltose, limit dextrin and various size of maltooligosaccharides in HPLC and TLC analysis. Commercial Sikhye was found to contain 0.09% of limit dextrin and 0.2% of rice residue. Limit dextrin in commercial Sikhye showed both signal of $\alpha$-1,4- and $\alpha$-1,6-glucosidic linkage with its estimation ratio of 15:1 by 1H-NMR analysis. This limit dextrin was hydrolyzed to produce various size of maltooligosaccarides with more longer chain than that of traditional Sikhye by pullulanase. Limit dextrin was digested wit enzymes(30units/ml) of $\alpha$-amylase, $\alpha$-glucosidase and glucoamylase from Aspergillus awamori, sweet potato $\beta$-amylase and human salivary $\alpha$-amylase at 37$^{\circ}C$ for 1 hour, respectively. Hydrolysis rates of these amylases on it were higher than in case of traditional sikhye. $\alpha$-Glucosidase plus human salivary $\alpha$-amylase hydrolyzed it to 61.3%. Hydrolysis rates of these amylases on rice residue were lower than that of traditional Sikye. These results suggest that limit dextrin in commercial Sikhye is less effective than isomaltooligosaccharides in traditional Sikhye as a growth factor for Bifidobacterium while rice residue in commercial Sikhye is more effective than that in traditional Sikhye as dietary fiber.ary fiber.