酶法生产低聚木糖的研究.pdf

贵州大学
硕士学位论文
晦法生产低聚木糖的研究
姓名:胡晓瑜
申请学位级别:硕士
专业:微生物学
指导教师:周文美
20080501
贵州大学2008届硕士学位论文
摘要
功能性食品的研究与开发给食品工业注入了全新的内容,而生产功能性食品
的关键是功能性食品基料即生理活性物质的制备。功能性低聚糖因具有独特的生
理功能,特别是能促进肠道内双岐杆菌的增殖,有益于肠健康而成为一种重要的
功能性食品基料,并己引起全世界的广泛关注。低聚木糖作为一种新型功能性低
聚糖已成为食品工业研究开发的热点之
本课题为获取低聚木糖,从菌种筛选、粗木聚糖生产、木聚糖酶制备、低聚
糖的生产各工艺阶段进行了探讨,以期为低聚木糖的生产研究做出贡献。研究中
首先采用了7种待测菌种作为木聚糖酶的生产菌,优化了粗木聚糖的制备条件,
采用透明圈法和DNS法测定了各种菌的产酶活性。获取适宜木聚糖酶生产菌种,
优化了产酶时程、氮源、p出值,并研究了温度对产酶过程的影响;初步确定了菌
种的发酵条件。纯化木聚糖酶后利用玉米芯生产的粗木聚糖和木聚糖酶生产低聚
木糖。最后对低聚木糖进行提取纯化,薄层层析法测定了低聚木糖成分。
本课题主要内容为
1)比较了三种球毛壳菌、一种血红毛売菌、一种舟形毛壳菌,以及米曲霉和白曲
霉等7株菌种的产酶效果。结果表明,米曲、血红毛壳
( Chaetomium cruentum)bob20-1和球毛壳菌ACCC30566有较好的产酶效果,
本课题主要以球毛壳菌ACCC30566作为产木聚糖酶的菌种。
2)通过单因素及正交实验,得出了粗木聚糖制备的最优条件:60℃漫泡1h,冷藏
8h-1h,乙醇洗涤用量为木聚糖溶液的2-3倍。
3)对自制粗木聚糖进行了含量测定,确定了各种条件下制得的粗木聚糖的纯度。
4)透明圈法初步测定各种实验菌的产酶酶活,结果表明球毛壳菌ACCC30566
米曲霉、血红毛壳( Chaetomium, cruentum)bob20-1产生的透明圈较为明显。
5)对木聚糖酶产酶时程进行研究,发现随着发酵时间的增加,底物木聚糖被降解,
木聚糖酶活性呈上升趋势。前2.5d酶活上升缓慢,2.5d后醇活急別升高,
3.5-4d时达到最大值。
贵州大学2008届硕土学位论文
6)氮源对产酶影响实验表明,不同氮源的培养基所产生的木聚糖酶酶活力顺序为:
蛋白胨>硝酸铵>氯化铵>硫酸铵>酵母膏,蛋白胨最有利于木聚糖酶的形
成
7)采用DNS法研究了州值2.2-10.67的范围内,不同叶值对5种毛壳菌木聚糖
酶活性的影响。结果表明,发酵3.5d-4d,pH值为7.25时木聚糖酶酶活力最
高,以蛋白胨为产酶培养基氮源时产酶效果最好。
8)确定了低聚木糖的生产工艺,以自制的木聚糖酶分解玉米芯粗木聚糖,得到低
聚木糖,并进行了纯化和成分测定
实验表明,贵州本地产玉米芯适合作为粗木聚糖的生产原料,本文所选菌种
的产酶效果较好,产生的木聚糖酶酶活力较高,适合低聚木糖生产,具有一定的
工业应用价值
关键词:玉米芯毛壳菌木聚糖木聚糖酶低聚木糖
贵州大学2008届硕士学位论文
ABSTRACTT
Since the functional oligosaccharides have some physiological functions, such as
promoting the multiplication of Bifidobacteria in intestine, keeping a good healthy for
people, the functional oligosaccharides have been attached important to by the people
Xylooligosaccharide is a kind of functional oligosaccharides, composed of 2-7 xylos
e. The link between the molecules is B-1, 4-xylosidate band. It can be prepared by r-xy
lanase reaction with corncob, cotton, seed hull or rapeseed hull. It's very difficult for
xylooligosaccharides digestion in intestines. The intestinal survivors of xylo oligosacc
ha rides are too much, and can keep a good multiplication for Bifidobacteria. The
utilization of the xylooligosaccharide is the highest among the other oligosaccharides
A maize is one of three main foodstuff plants in China. The average yield of the comcob
is very big. Most of the corncobs are bumt, although a few are used. It's very important
to do the research about the xylooligosaccharides preparation with corncobs
This text adopt Chaetomium which are not appear in the newspapers and dish
reco-r
rd in china to product t xylanase, on the basis of optimizing the preparation
condition of xylan, combine transparent enclose law and DNS law determine of
different fungus s activity to produce the enzyme. This paper studied the eftects of
culture time, culture temperature, nitrogen source, and pl on the activity of
xylanase. The experiment is explored the fermented condition for the new
fungus Purified the xylanase to produce xylooligosaccharide. Then purify the
xylooligosaccharide, TC to analyse composition of different xylooligosaccharides
finall
The concrete content is as follows
1)select for use Chaetomium which are not appear in the newspapers and dish record in
china, Asp. oryzae and Aspergillus candid