- An innovative method for immobilizing sucrose isomerase on ε-poly-L-lysine modified mesoporous TiO2
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Sucrose isomerase (SIase) is the key enzyme in the enzymatic synthesis of isomaltulose. Mesoporous titanium dioxide (M-TiO2) and ε-poly-L-lysine-functionalized M-TiO2 (EPL-M-TiO2) were prepared as carriers for immobilizing SIase. SIase was effectively immobilized on EPL-M-TiO2 (SI-EPL-M-TiO2) with an enzyme activity of 39.41 U/g, and the enzymatic activity recovery rate up to 93.26%. The optimal pH and temperature of immobilized SIase were 6.0 and 30 °C, respectively. SI-EPL-M-TiO2 was more stable in pH and thermal tests than SIase immobilized on M-TiO2 and free SIase. Km of SI-EPL-M-TiO2 was 204.92 mmol/L, and νmax was 45.7 μmol/L/s. Batch catalysis reaction of sucrose by SI-EPL-M-TiO2 was performed under the optimal conditions. The half-life period of SI-EPL-M-TiO2 under continuous reaction was 114 h, and the conversion rate of sucrose after 16 batches consistently remained at around 95%, which indicates that SI-EPL-M-TiO2 has good operational stability. Thus, SI-EPL-M-TiO2 can be used as a biocatalyst in food industries.
- Wu, Lingtian,Liu, Yi,Chi, Bo,Xu, Zheng,Feng, Xiaohai,Li, Sha,Xu, Hong
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- Mechanism-Oriented Redesign of an Isomaltulose Synthase to an Isomelezitose Synthase by Site-Directed Mutagenesis
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An isomelezitose synthase was redesigned out of the sucrose isomerase from Protaminobacter rubrum for the synthesis of isomelezitose (6-OF-glucosylsucrose), a potential nutraceutical. The variants F297A, F297P, R333K, F321A-F319A and E428D catalyze the formation of isomelezitose in up to 70% yield.
- Goerl, Julian,Timm, Malte,Seibel, Juergen
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- Production of keto-disaccharides from aldo-disaccharides in subcritical aqueous ethanol
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Isomerization of disaccharides (maltose, isomaltose, cellobiose, lactose, melibiose, palatinose, sucrose, and trehalose) was investigated in subcritical aqueous ethanol. A marked increase in the isomerization of aldo-disaccharides to keto-disaccharides was noted and their hydrolytic reactions were suppressed with increasing ethanol concentration. Under any study condition, the maximum yield of keto-disaccharides produced from aldo-disaccharides linked by β-glycosidic bond was higher than that produced from aldo-disaccharides linked by α-glycosidic bond. Palatinose, a keto-disaccharide, mainly underwent decomposition rather than isomerization in subcritical water and subcritical aqueous ethanol. No isomerization was noted for the non-reducing disaccharides trehalose and sucrose. The rate constant of maltose to maltulose isomerization almost doubled by changing solvent from sub-critical water to 80 wt% aqueous ethanol at 220°C. Increased maltose monohydrate concentration in feed decreased the conversion of maltose and the maximum yield of maltulose, but increased the productivity of maltulose. The maximum productivity of maltulose was ca. 41 g/(h kg-solution).
- Gao, Da-Ming,Kobayashi, Takashi,Adachi, Shuji
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p. 998 - 1005
(2016/05/09)
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- Microorganisms having enhanced sucrose mutase activity
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The invention relates to the biotechnological production of isomaltulose and isomaltulose-containing compositions and improved means, therefore particularly microbial cells.
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Page/Page column
(2014/08/06)
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- Enzymatic synthesis of l-DOPA α-glycosides by reaction with sucrose catalyzed by four different glucansucrases from four strains of Leuconostoc mesenteroides
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Synthesized by reaction of Leuconostoc mesenteroides B-512FMC, B-742CB, B-1299A dextransucrases, and B-1355C alternansucrase with sucrose and l-DOPA α-glycosides were synthesized by reaction of l-DOPA with sucrose, catalyzed by four different glucansucras
- Yoon, Seung-Heon,Fulton, D. Bruce,Robyt, John F.
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experimental part
p. 1730 - 1735
(2010/10/19)
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- Method for preparing crystalline isomaltulose and hydrogenated isomaltulose
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Provided is a method for manufacturing crystalline isomaltulose from sucrose, comprising the steps of: 1) contacting an α-glucosyltransferase enzyme to aqueous sucrose solution or slurry under the condition wherein the α-glucosyltransferase enzyme is active; in which said condition is maintained after the concentration of isomaltulose in the reaction mixture reaches the point at which crystals are formed, and 2) separating the reaction mixture into crystalline isomaltulose and remaining syrup. According to the present invention, enzymatic conversion of sucrose and crystallization of isomaltulose are carried out simultaneously in a same reaction vessel. In addition, the enzyme can be used repeatedly.
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Page/Page column 5-6
(2008/06/13)
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- Hydrolysis of low-molecular-weight oligosaccharides and oligosaccharide alditols by pig intestinal sucrase/isomaltase and glucosidase/maltase
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The ability of purified pig intestinal sucrase/isomaltase (SI; EC 3.2.1.10/48) and glucosidase/maltase (GM; EC 3.2.1.20) to hydrolyze di- and oligosaccharides consisting of D-glucose and D-fructose residues and the corresponding alditols was studied. The products, after incubation, reflect different binding patterns at both catalytic sites of SI. The active site of the sucrase subunit cleaves α,β-(1→2) glycosidic bonds, and only two monomer units of the substrates bind with favorable affinity. Oligosaccharides and reduced oligosaccharides containing α-(1→6) and α-(1→1) glycosidic bonds are hydrolyzed by isomaltase, and for the active site of this subunit more than two subsites were postulated. Moreover, different binding sites for various aglycons seem to exist for isomaltase. Oligosaccharide alcohols are cleaved at lower rates if the reduced sugar residue occupies the aglycon binding site. GM also hydrolyzes α-(1→1) linkages, but at a lower rate. The enzyme has the ability to bind compounds containing residues other than D-glucose. There are indications for similarities between GM and the isomaltase subunit of SI in the binding mode of oligosaccharides. Copyright (C) 2000 Elsevier Science Ltd.
- Hertel, Sabine,Heinz, Fritz,Vogel, Manfred
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p. 264 - 276
(2007/10/03)
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