Preparation of lactose-free pasteurized milk with a recombinant thermostable β-glucosidase from Pyrococcus furiosus.
Preparation of lactose-free pasteurized milk with a recombinant thermostable β-glucosidase from Pyrococcus furiosus.
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DOI：
10.1186/1472-6750-13-73
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发表时间：
2013-09-21
影响因子：
3.5
通讯作者：
Tang D
中科院分区：
文献类型：
--
作者：
Li B;Wang Z;Li S;Donelan W;Wang X;Cui T;Tang D
乳糖不耐受是一种常见的健康问题，会导致胃肠道症状和患者回避乳制品。由于牛奶是钙和维生素 D 的主要来源，乳糖不耐受的人通常无法获得足够的这些营养素，这可能会导致不良的健康后果。生产无乳糖牛奶可以解决这个问题，尽管它需要使用微生物来源的乳糖酶并增加污染的可能性。使用热稳定性乳糖酶可以通过在巴氏灭菌条件下发挥作用来克服这个问题。来自激烈火球菌的热稳定性 β-葡萄糖苷酶基因与酿酒酵母 a 因子分泌信号符合读码框克隆，并在巴斯德毕赤酵母菌株 X-33 中表达。采用弱阴离子交换层析一步法纯化重组酶。该 β-葡萄糖苷酶活性的最适温度和 pH 值分别为 100°C 和 pH 6.0。 Ca2+对酶活性没有显着抑制。我们测试了巴氏灭菌过程中的添加量、水解时间以及葡萄糖对酶的影响，发现该酶对牛奶中的乳糖具有较高的水解水平，且不受葡萄糖的影响明显。这种重组β-葡萄糖苷酶的热稳定性，结合其中性pH活性和有利的温度活性最佳值，表明该酶是牛奶中乳糖水解的理想候选酶，并且适合在巴氏灭菌过程中应用于低乳糖牛奶生产。
Lactose intolerance is a common health concern causing gastrointestinal symptoms and avoidance of dairy products by afflicted individuals. Since milk is a primary source of calcium and vitamin D, lactose intolerant individuals often obtain insufficient amounts of these nutrients which may lead to adverse health outcomes. Production of lactose-free milk can provide a solution to this problem, although it requires use of lactase from microbial sources and increases potential for contamination. Use of thermostable lactase enzymes can overcome this issue by functioning under pasteurization conditions. A thermostable β-glucosidase gene from Pyrococcus furiosus was cloned in frame with the Saccharomyces cerecisiae a-factor secretory signal and expressed in Pichia pastoris strain X-33. The recombinant enzyme was purified by a one-step method of weak anion exchange chromatography. The optimum temperature and pH for this β-glucosidase activity was 100°C and pH 6.0, respectively. The enzyme activity was not significantly inhibited by Ca2+. We tested the additive amount, hydrolysis time, and the influence of glucose on the enzyme during pasteurization and found that the enzyme possessed a high level of lactose hydrolysis in milk that was not obviously influenced by glucose. The thermostablity of this recombinant β-glucosidase, combined with its neutral pH activity and favorable temperature activity optima, suggest that this enzyme is an ideal candidate for the hydrolysis of lactose in milk, and it would be suitable for application in low-lactose milk production during pasteurization.
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影响因子：
3.5
作者：
Waterham, HR;Digan, ME;Cregg, JM
通讯作者：
Cregg, JM
DOI：
10.1111/j.1432-1033.1993.tb17763.x
发表时间：
1993-04-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
KENGEN, SWM;LUESINK, EJ;ZEHNDER, AJB
通讯作者：
ZEHNDER, AJB
影响因子：
2.8
作者：
Zhang, Ai-Lian;Luo, Jin-Xian;Tu, Fa-zhi
通讯作者：
Tu, Fa-zhi
影响因子：
1.6
作者：
Cieslinski, H;Kur, J;Turkiewicz, M
通讯作者：
Turkiewicz, M
DOI：
10.1111/j.1432-1033.1981.tb05193.x
发表时间：
1981-01-01
期刊：
EUROPEAN JOURNAL OF BIOCHEMISTRY
影响因子：
--
作者：
SKOVBJERG, H;SJOSTROM, H;NOREN, O
通讯作者：
NOREN, O