土曲霉lovastatin高产菌的基因组重排育种

生物工程论文编号:SW132  论文字数:15046,页数:29

目  录

中文摘要 ………………………………………………………………………………………Ⅰ
英文摘要 ………………………………………………………………………………………Ⅱ
目录 ……………………………………………………………………………………………Ⅲ
1  绪论…………………………………………………………………………………………..1
      1.1 前言 …………………………………………………………………………………..1
 1.2 伐他汀的概况…………………………………………………………………………1
     1.3 洛伐他汀生产菌的菌种选育…………………………………………………………3
 1.4 本文的研究目标和思路 …………………………………………………………….7
2 实验部分 …………………………………………………………………………………….8
    2.1 材料  …………………………………………………………………………………8
 2.2 实验仪器 …………………………………………………………………………….9
 2.3 方法 ………………………………………………………………………………….9
3结果与讨论 …………………………………………………………………………………15
 3.1 菌株筛选方法的建立 ………………………………………………………………15
 3.2 突变体原生质体的制备条件研究 …………………………………………………17
 3.3 基因组重排育种 ……………………………………………………………………19
4 总结与展望………………………………………………………………………………….22
致谢  ………………………………………………………………………………………….23
参考文献……………………………………………………………………………………….24

摘要：洛伐他汀（lovastatin）是土曲霉（Aspergillus terreus）所产生的一种降血脂物质，它通过抑制体内胆固醇生物合成的关键酶HMG—CoA还原酶的活性而发挥作用。目前土曲霉菌种的发酵产量普遍偏低，本文将一种较新的育种方式基因组重排用于土曲霉菌种的选育，以提高其洛伐他汀的产量。初步探讨了耐前体和耐自身代谢产物突变株的筛选方法，对土曲霉原生质体的制备条件进行了研究，考察了菌体菌龄、酶种类、酶浓度等对土曲霉原生质体制备的影响。用紫外线灭活和热灭活对原生质体进行了灭活并初步进行了基因组重排实验。经过两轮基因组重排实验初步获得了具有潜在高产性能的10株抗性菌株（其中耐乙酸钠前体的抗性菌株6株，耐Lovastatin的抗性菌株4株）。
 
 
关键词: 土曲霉；洛伐他汀；紫外诱变；化学诱变；基因组重排
Genome shuffling of Aspergillus terreus for lovastatin production

Abstract: Lovastatin, as an important blood-lipid-lowering substance, was produced by Aspergillus terreus and other molds. It acts as inhibitor by inhibiting the enzyme activity of HMG-CoA, which is a key enzyme of cholesterol biosynthesis. Since the fermentation yield of Aspergillus terreus strain is generally low, it is necessary to carry out strain breeding. In this paper, a relatively new breeding methods genome shuffling was sued for the strain breeding of Aspergillus terreus. The precursors and the metabolites resistant mutant selection method used for strain selection were explored and the protoplast preparation conditions of Aspergillus terreus strain were studied. Through two cycles of genome shuffling, ten strains with potential high yield were obtained.
 
 
 Key words: Aspergillus terreus; Lovastatin; UV mutagenesis; Chemical mutagenesis; Genome shuffling