β-甘露聚糖酶产生菌的筛选及魔芋低聚糖制备工艺的研究  

Screening of β-mannanase producing strain and preparation technology of konjac oligosaccharides

作　　者：郭金玲[1,2,3] 张丹阳 樊雪莲 吕育财 田毅红[1,2,3] 龚大春 GUO Jinling;ZHANG Danyang;FAN Xuelian;LV Yucai;TIAN Yihong;GONG Dachun(Hubei Engineering Research Center for Biological Jiaosu(HERC-BJ),China Three Gorges University,Yichang 443002,China;Yichang Key Laboratory of Biocatalysis,China Three Gorges University,Yichang 443002,China;College of Biological and Pharmaceutical Sciences,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学湖北省生物酵素工程技术研究中心,湖北宜昌443002 [2]三峡大学生物催化宜昌市重点实验室,湖北宜昌443002 [3]三峡大学生物与制药学院,湖北宜昌443002

出　　处：《中国酿造》2018年第8期123-127,共5页China Brewing

基　　金：湖北省教育厅科学技术研究项目(D20171206)

摘　　要：以魔芋粉为唯一碳源,从种植魔芋土壤中定向筛选一株高产胞外β-甘露聚糖酶的菌株,进行形态观察、生理生化试验和16S r DNA序列分析鉴定,并研究了该β-甘露聚糖酶水解魔芋胶制备魔芋低聚糖的工艺。结果表明,筛选出一株高产胞外β-甘露聚糖酶的菌株,编号为G1,被鉴定为枯草芽孢杆菌(Bacillus subtilis)。确定魔芋低聚糖制备的酶解条件为酶添加量50 U/g魔芋葡甘聚糖(KGM),酶解p H值6.5,酶解温度55℃;当KGM质量浓度为10 g/L,酶解时间2 h时,还原糖转化率为51.6%;当KGM质量浓度为30 g/L,酶解时间4 h时,还原糖转化率仍可达到46.9%,表明该酶具有较高的催化效率。利用薄层层析(TLC)定性分析酶解产物主要为三糖及三糖以上的低聚糖。该研究为实现酶法制备魔芋低聚糖的工业化生产奠定了基础。Using konjac powder as single carbon source,a strain with high-yield extracellularβ-mannanase was screened from soil planted konjac and identified by morphological observation,physiological and biochemical tests and 16S rDNA sequence analysis.At the same time,preparation technology of konjac oligosaccharides was studied by usingβ-mannanase enzymatic hydrolysis amorophophallus konjac.Results showed that strain G1 with high-yield extracellularβ-mannanase was screened and identified as Bacillus subtilis.The enzymatic hydrolysis conditions of preparation of konjac oligosaccharides were determined as follows:β-mannanase addition 50 U/g konjac glucomannan(KGM),enzymatic hydrolysis pH value 6.5,temperature 55℃.When the concentration of KGM was 10 g/L and the hydrolysis time was 2 h,the conversion rate of reducing sugar was 51.6%.When the concentration of KGM was 30 g/L and the hydrolysis time was 4 h,the conversion rate of reducing sugar could still reach 46.9%,indicating that theβ-mannanase has higher catalytic efficiency.Enzymolysis hydrolysis products were qualitatively analyzed by thin layer chromatography(TLC)and revealed that enzymolysis hydrolysis products were mainly composed of oligosaccharide with trisaccharide and more than trisaccharide.This study laid the foundation for industrial production of konjac oligosaccharides which were prepared by enzymatic hydrolysis.

关 键 词：Β-甘露聚糖酶 魔芋胶 筛选 葡甘露低聚糖 酶解条件 

分 类 号：Q814.9[生物学—生物工程]