利用纤维二糖差向异构酶制备乳果糖的研究进展

Advances in bio-production of lactulose using cellobiose 2-epimerases

摘要:

乳果糖是由D-半乳糖和D-果糖两个基团通过β-1，4糖苷键连接而成的还原型二糖；乳果糖口服液具有治疗慢性便秘和肝性脑病的功效，在100多个国家作为常见非处方药（OTC）使用，需求量十分巨大；乳果糖还可以作为益生元改善人体肠道菌群关系。乳果糖的生产依赖化学法，其催化剂对人体有害，下游分离难度大。近年来，纤维二糖差向异构酶被发现能够高效催化乳糖制备乳果糖，该技术绿色环保、步骤简单，具有很强的产业化前景。本文结合自身研究经历对纤维二糖差向异构酶的研发情况进行总结，并综述了乳果糖酶法制备技术的现状。

Abstract:

Lactulose, a reducing disaccharide, is composed of D-galactosyl and D-fructosyl moieties via the ligation of a β-1,4 glycosidic bond. The concentrated lactulose solution can be used to treat chronic constipation and hepatic encephalopathy. It is an over-the-counter drug (OTC) worldwide, resulting in a massive requirement for its production. Lactulose is also a prebiotic that benefits human intestinal flora. Current industrial production of lactulose relies on chemical catalysis, with harmful catalyst and difficult in the down-stream processing. Recently, cellobiose 2-epimerase (CE) is recognized as an efficient biocatalyst for lactulose production using lactose as the substrate. This technique is environmentally friendly and composed of simpler procedures, showing promising future for an industrial application. This paper reviews recent developments in CE enzyme research, and the biotechnological route of lactulose synthesis.