Efficient production of lactulose from whey powder by cellobiose 2-epimerase in an enzymatic membrane reactor
Efficient production of lactulose from whey powder by cellobiose 2-epimerase in an enzymatic membrane reactor
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在酶膜反应器中通过纤维二糖 2-差向异构酶从乳清粉高效生产乳果糖
DOI：
10.1016/j.biortech.2017.02.089
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发表时间：
2017-06-01
影响因子：
11.4
通讯作者：
Xu, Zheng
中科院分区：
文献类型：
--
作者：
Wu, Lingtian;Xu, Cen;Xu, Zheng
在这项研究中，来自解糖热解纤维素酶（CsCE）的编码纤维二糖2-差向异构酶的基因在枯草芽孢杆菌WB800中成功表达。发酵培养基优化后，重组菌株在7.5 L发酵罐中的活性比原培养基高4.5倍。粗CsCE的最佳催化pH和温度分别为7.0和80℃。使用奶酪乳清乳糖作为底物开发了乳果糖的酶法合成。使用 7.5 U/mL CsCE 获得的乳清粉的最大转化率为 58.5%。酶膜反应器系统表现出良好的操作稳定性，10 个批次后乳糖转化率较高（42.4%），这证实了这一点。据了解，这是首次报道食品级菌株合成乳果糖，提高了食品安全性，不仅实现了乳果糖的生物生产，而且很好地利用了工业废弃物，对环境产生了积极的影响。 (C) 2017 Elsevier Ltd. 保留所有权利。
In this study, the gene encoding cellobiose 2-epimerase from Caldicellulosiruptor saccharolyticus (CsCE) was successfully expressed in Bacillus subtilis WB800. After the fermentation medium optimization, the activity of recombinant strain was 4.5-fold higher than the original medium in a 7.5 L fermentor. The optimal catalytic pH and temperature of crude CsCE were 7.0 and 80 degrees C, respectively. An enzymatic synthesis of lactulose was developed using cheese-whey lactose as its substrate. The maximum conversion rate of whey powder obtained was 58.5% using 7.5 U/mL CsCE. The enzymatic membrane reactor system exhibited a great operational stability, confirmed with the higher lactose conversion (42.4%) after 10 batches. To our best knowledge, this is the first report of lactulose synthesis in food grade strain, which improve the food safety, and we not only realize the biological production of lactulose, but also make good use of industrial waste, which have positive impact on environment. (C) 2017 Elsevier Ltd. All rights reserved.