《产菊粉酶菌株的选育及其产酶条件的研究》由会员分享，可在线阅读，更多相关《产菊粉酶菌株的选育及其产酶条件的研究（63页珍藏版）》请在金锄头文库上搜索。
1、河南科技大学硕士学位论文产菊粉酶菌株的选育及其产酶条件的研究姓名：曾小宇申请学位级别：硕士专业：生物化学与分子生物学指导教师：刘建学;罗登林20091201摘 要 I论文题目： 产菊粉酶菌株的选育及其产酶条件的研究 论文题目： 产菊粉酶菌株的选育及其产酶条件的研究 专 业： 生物化学与分子生物学 专 业： 生物化学与分子生物学 研 究 生： 曾小宇 研 究 生： 曾小宇 指导教师： 刘建学 、罗登林 指导教师： 刘建学 、罗登林 摘 要 摘 要 菊粉由 D-果糖经 （12）键连接而成的多糖，利用菊粉作原料通过菊粉酶一步法降解可直接制得低聚果糖和超高纯度果糖浆。低聚果糖是一类天然性的功能低聚糖，
2、它具有改善肠道微环境、调控血脂和血糖水平、预防肥胖症、促进矿物质吸收和维生素合成等突出生理功能；而果糖具有甜度高且风味纯正、抗龋齿、代谢途径不受胰岛素控制等优点。目前自然界中能产菊粉酶的微生物很多，但真正能够高产菊粉酶的菌株却很少，为了获得一株高产菊粉酶菌株，本文主要开展了以下三个方面的研究： 1. 超声强化提取菊芋中菊粉的研究 为了探讨超声对菊芋中菊粉提取的影响，试验采用单因素试验和响应曲面法对其提取工艺进行了研究，建立并分析了各主要影响因子与菊粉提取率关系的数学模型。试验结果显示，回归方程 p=0.000210.01，决定系数 R2为 98.94%，说明所建模型与试验值的拟合度很好。超声提
3、取菊粉的优化工艺为：总提取时间为 10min，超声辐照方式为 15s/6s，超声功率为 750W，料液比(w/v)为 1: 30.15，提取温度为 40，在此条件下菊粉的提取率为 94.23%。与常规热水提取法相比，提取率提高了 26.25 个百分点。 2. 产菊粉酶菌株的选育 为了获得一株高产菊粉酶的菌株，试验从菊芋根际土壤和叶子中通过初筛、分离纯化和摇瓶复筛的方法筛选出一株产菊粉酶最高的菌株，并鉴定其为黑曲霉属。然后通过紫外线诱变、微波诱变、化学试剂诱变等三种方法对所筛选出的菌株进行诱变，最终筛选出通过微波诱变所获得的产酶活力最高的诱变株为下一步试验菌株，测得其酶活力为 15.61U/mL
4、，与原始出发菌株的酶活力相比提高了78.20%。 3. 诱变菌株黑曲霉产菊粉酶条件的研究 为了确立黑曲霉产菊粉酶条件的最优工艺参数，试验选取麸皮添加量、菊粉添加量、蛋白胨添加量、酵母膏添加量、发酵时间、温度、pH 值、接种量等 8个相关因素，首先通过 Plackett-Burmen 试验设计筛选出三个显著因子：麸皮添加量(P=0.027741)、发酵时间(P=0.029919)、pH 值(P=0.012346)。然后通过 Box-摘 要 IIBehnken 试验设计对三个显著因素进行响应面优化并建立和分析了各主要影响因子与黑曲霉产酶活力关系的数学模型。试验结果显示，回归方程 p=0.00010
5、.01，决定系数 R2为 99.62%，说明所建模型与试验值的拟合度很好。黑曲霉产酶活力的优化工艺为麸皮添加量 4.64%，发酵时间 81.5h，pH 值 6.0。在此工艺参数下，菌种产酶活力达 20.42U/mL。与未优化前相比，菌种的产酶活力从15.61 U/mL 增加到 20.42 U/mL ，提高了 30.81%。 关 键 词：菊粉，超声提取，菊粉酶，选育，黑曲霉关 键 词：菊粉，超声提取，菊粉酶，选育，黑曲霉 论文类型：应用基础研究 论文类型：应用基础研究 摘 要 IIISubject: Research on inulinase strains breeding and its f
6、ermentation Specialty: Biochemistry and Molecular Biology Name: Zeng Xiao-Yu Supervisor: Liu Jian-Xue Luo Deng-Lin ABSTRACT Inulin is a polysaccharide of D-fructose joined by (21) linkages, producing fructooligosaccharides and ultra-high purity fructose syrup directly by one-step method using inulin
7、ase. The fructooligosaccharide is a kind of natural functional polysaccharide, its physiological functions are as follows: improving intestinal microenvironment, controlling blood sugar and blood lipid levels, preventing adiposis and prompting minerals absorption and vitamins biosynthesis. Fructose
8、has many features such as sweetness, high purity flavor, anti-dental caries, its metabolic pathways was uncontrol by insulin and so on. Currently, there are many kinds of nature microbiology producing inulinase but the high-yielding strains are rare. Three main studies were carried out in this paper
9、 to get high-yielding inulinase strains: 1. Ultrasound-enhanced extraction of inulin in Helianthus Tuberosus L. To investigate the impact of ultrasound-assisted extraction of inulin from Helianthus Tuberosus L. Experiment design employed single factor experiments and response surface methodology (RS
10、M). A mathematical model was developed and analyzed to describe the relationships between the main factors and the response of the inulin extraction yield. The results of experiments showed that the p value was 0.00021 lower than 0.01 and the R2 value was 98.94% from the regression model. It indicat
11、ed that the model was adequate to describe the experimental value. The yield of inilin extracted by ultrasound reached 94.23% at an optimum conditions of the total extraction time 10 minutes, the ultrasonic irradiation mode 15s/6s, the ultrasonic power 750W, the ratio of solvent to material (v/w) wa
12、s 1:30.15 and extraction temperature 40. The extraction yield increased by 26.25 percentage points compared with the Conventional hot water extraction. 2. Breeding the strains for producing inulinase To obtain a high-yielding inulinase strains, experiment screening the highest yielding inulinase str
13、ains from the rhizosphere soil and leaves of Helianthus Tuberosus L. by initial screening, purification and complex screening of shake-flask and identify 摘 要 IVas the Aspergillus niger. And then mutagenized the selected strains by UV mutagenesis, microwave mutagenesis and chemical mutagenesis. Event
14、ually, it obtained the highest-yielding inulinase mutational strains for the next experiment by microwave mutagenesis. The enzyme activity of the strains was 15.61U/mL, it increased by 78.20% compared to the original strains. 3. Research on fermentation conditions of the mutagenic Aspergillus niger
15、for inulinase The aim of our research was to establish the optimum polytechnic parameters of the fermentation conditions. First, we worked out the Plackett-Burmen design to find the key factors from the following eight effective factors on fermentation: the content of wheat bran, inulin, peptone, yeast extract, fermentation time, temperature, pH, and inoculum size, the result indicated that the content of wheat bran(p=0.027741), fermentation time(p=0.029919) and pH(p=0.012346) were significant factor
