Levan果聚糖的应用与生产研究进展  

Progress on the application and production of levan

作　　者：陆娟[1] 唐俊[1] 肖敏[2] 屈长青[1] 

机构地区：[1]阜阳师范学院生命科学学院,阜阳236037 [2]山东大学微生物技术国家重点实验室国家糖工程技术研究中心,济南250100

出　　处：《生物学杂志》2013年第6期86-90,共5页Journal of Biology

基　　金：国家自然科学基金项目(No.41001189;31070064);校级产学研重点项目(No.2010CXY02)

摘　　要：Levan是一类果聚糖,由大量的果糖单元以β-(2,6)果糖苷键连接构成聚糖主链并含有少量β-(2,1)果糖苷键连接的支链组成。部分微生物来源的Levan具有抗肿瘤、抗病毒、降血糖、降血脂、免疫增强等重要的生物活性,在医药和功能性食品方面具有巨大的应用潜能。微生物发酵液提取和酶法合成是目前大量获得Levan果聚糖的两种方法,其中微生物发酵液提取的Levan果聚糖产量和蔗糖转化率一般较低,且发酵液中同时存在的其他高聚物不利于Levan的规模化纯化;而利用Levan蔗糖酶以蔗糖为底物转果糖基合成的Levan果聚糖产量已经高达200g/L、蔗糖转化率高达50%,并且Levan蔗糖酶合成Levan过程中酶的活性受到pH值、温度、螯合剂、金属离子等多种因素的影响,可以通过控制反应条件促进多糖合成反应的进行。因此,酶法合成将是工业化获得Levan果聚糖的主要方式。Levan is one of fructans mainly linked by β-（ 2,6）-glycosidic bonds with some β-（ 2,1）-linked branch chains. Levan obtained from microorganisms has shown to possess biological activities such as antitumor activities,antiviral activity,antidiabetic activity,hypolipidemic effect and immunological enhancement activity. So it has a wide and potential application in the pharmaceutical and food industry. In order to obtain levan in large scale,two main approaches of levan obtaining from microbial fermentation broth and enzymatic synthesis are usually employed. In the former levan extraction yield and sucrose conversion rates are generally lower,and the other polymers existing alongside in the fermentation broth are not conductive to levan purification in large scale. But in the latter, levansucrases use sucrose as their main substrate and transfer fructose to synthesis levan,levan yield and sucrose conversion rate get up to 200 g/l and 50% respectively. And the activity of levansucrase was usually affected by some factors such as pH,temperature,chelating agents and metal ions,and the reaction conditions could be artificially controlled to facilitate the levan synthesis. Therefore,enzymatic synthesis will be the principal means to obtain levan in industry.

关 键 词：LEVAN 应用 生产 酶法合成 

分 类 号：Q539[生物学—生物化学] Q93