高山被孢霉高产花生四烯酸菌株的硫酸二乙酯诱变育种
时间:2021-04-19 22:48 来源:毕业论文 作者:毕业论文 点击:次
摘 要:花生四烯酸是一种ω-6系列长链多不饱和脂肪酸,具有重要的生物活性和营养作用。其传统来源有限且提取率低提取成本较高,导致其不能满足市场需求。微生物发酵法是制备花生四烯酸的新途径,此方法的核心问题是高产菌株的筛选。本论文以产花生四烯酸的高山被孢霉为出发菌株,采用硫酸二乙酯进行诱变,利用TTC染色法和气相色谱分析法分别进行初筛和复筛,最终获得了一株花生四烯酸高产菌株DES-25-4,其油脂得率可达到199 mg/g干菌体,比原始菌株提高了13.35%;其花生四烯酸含量达到11.26%,比原始菌株提高了9.52%;遗传稳定学实验表明,DES-25-4遗传稳定。本论文的研究可为花生四烯酸的生产提供菌株的选择。65906 毕业论文关键词:花生四烯酸,高山被孢霉,硫酸二乙酯诱变
Abstract:Arachidonic acid (AA) is a kind of long-chain polyunsaturated fatty acids of ω-6. It has an important role in biological activity. But the traditional source is limited and it costs too much to extract from them. Microbial fermentation is a new way to produce AA. The key is to screen high-yield strains in microbial fermentation. The aim of the experiment is to screen high-yield strains. In the experiment, Mortierella alpina producing AA was mutated by diethyl sulfate to improve the yield of producing AA. After screening repeatedly, a mutant DES-25-4 with high yield of lipid and AA was obtained. Comparing with the original strain, the yield of lipid increased by 13.35%, and the AA yield increased by 9.52%. Strain DES-25-4 had a good hereditary stability after several generations. Keyword: Arachidonic acid, Mortierella alpina, Mutation by diethyl sulfate 目 录
1 前言 4 2 材料与方法 8 2.1 实验材料 8 2.2 实验方法 9 2.2.1 菌种保藏方法 9 2.2.2 菌种活化方法 9 2.2.3 硫酸二乙酯(DES)诱变方法 9 2.2.4 初筛方法 9 2.2.5 红四氮唑染色法(TTC)检测花生四烯酸含量方法 9 2.2.6 复筛方法 10 2.2.7 突变株遗传稳定性的测定方法 11 3 结果与分析 12 3.1 硫酸二乙酯诱变致死率结果 12 3.2 硫酸二乙酯诱变的初筛结果 12 3.3 硫酸二乙酯诱变的复筛结果 15 3.4 突变菌株的遗传稳定性结果 15 4. 结论与展望 17 4.1 结论 17 4.2 展望 17 参 考 文 献 18 致 谢 20 1 前 言 1.1 花生四烯酸及高山被孢霉的简介 (责任编辑:qin) |