Selective Synthesis of Galactooligosaccharides Containing β(1→3) Linkages with β-Galactosidase from Bifidobacterium bifidum (Saphera)
Selective Synthesis of Galactooligosaccharides Containing β(1→3) Linkages with β-Galactosidase from Bifidobacterium bifidum (Saphera)
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DOI：
10.1021/acs.jafc.0c00997
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发表时间：
2020-04-29
影响因子：
6.1
通讯作者：
Plou, Francisco J.
中科院分区：
文献类型：
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作者：
Fureder, Vera;Rodriguez-Colinas, Barbara;Plou, Francisco J.
对一种新的商业化的两歧双歧杆菌（Saphera）β-半乳糖苷酶的转糖基化活性进行了评价。用邻硝基苯基-β-D-吡喃半乳糖苷测定，该酶的最佳操作条件为40 ℃，pH约6.0。虽然在低乳糖浓度下，该酶的性质基本上是水解的，但乳糖浓度增加到400 g/L导致益生元低聚半乳糖（GOS）的显著形成（107.2 g/L，27%产率）。在大约90%的乳糖转化率下获得最大量的GOS，这与其他β-半乳糖苷酶形成对比，对于其他β-半乳糖苷酶，在40-50%的乳糖转化率下获得最高的GOS产率。使用高效阴离子交换色谱脉冲安培检测，半制备高效液相色谱-亲水相互作用液相色谱，质谱，和1D和2D NMR，我们确定了大多数的GOS的结构由这种酶合成。主要产物为Gal-β（1 -> 3）-Gal-β（1 -> 4）-Glc（3 '-O-β-半乳糖基-乳糖），Gal-β（1 -> 6）-Glc（异乳糖），半乳糖-β（1 -> 3）-葡萄糖Gal-β（1 -> 3）-Gal（3-半乳糖二糖）和四糖Gal-β（1 -> 3）-Gal-β（1-> 3）-Gal-β（1 -> 4）-Glc。一般来说，B.双歧杆菌β-半乳糖苷酶显示出形成β（1 -> 3）键的趋势，然后是β（1 -> 6）键，更少的是β（1 -> 4）键。
The transglycosylation activity of a novel commercial beta-galactosidase from Bifidobacterium bifidum ( Saphera) was evaluated. The optimal conditions for the operation of this enzyme, measured with o-nitrophenyl-beta-D-galactopyranoside, were 40 degrees C and pH around 6.0. Although at low lactose concentrations the property of this enzyme was basically hydrolytic, an increase of lactose concentration to 400 g/L resulted in a significant formation (107.2 g/L, 27% yield) of prebiotic galactooligosaccharides (GOS). The maximum amount of GOS was obtained at a lactose conversion of approximately 90%, which contrasts with other beta-galactosidases, for which the highest GOS yield is achieved at 40-50% lactose conversion. Using high-performance anion-exchange chromatography with pulsed amperometric detection, semipreparative high-performance liquid chromatography-hydrophilic interaction liquid chromatography, mass spectrometry, and 1D and 2D NMR, we determined the structure of most of the GOS synthesized by this enzyme. The main identified products were Gal-beta(1 -> 3)-Gal-beta(1 -> 4)-Glc (3'-O-beta-galactosyl-lactose), Gal-beta(1 -> 6)-Glc (allolactose), Gal-beta(1 -> 3)-Glc (3-galactosyl-glucose), Gal-beta(1 -> 3)-Gal (3-galactobiose), and the tetrasaccharide Gal-beta(1 -> 3)-Gal-beta(1 -> 3)-Gal-beta(1 -> 4)-Glc. In general, B. bifidum beta-galactosidase showed a tendency to form beta(1 -> 3) linkages followed by beta(1 -> 6) and more scarcely beta(1 -> 4).