土曲霉lovastatin高產(chǎn)菌的基因組重排育種

生物工程論文編號:SW132  論文字?jǐn)?shù):15046,頁數(shù):29

目  錄

中文摘要 ………………………………………………………………………………………Ⅰ
英文摘要 ………………………………………………………………………………………Ⅱ
目錄 ……………………………………………………………………………………………Ⅲ
1  緒論…………………………………………………………………………………………..1
      1.1 前言 …………………………………………………………………………………..1
 1.2 伐他汀的概況…………………………………………………………………………1
     1.3 洛伐他汀生產(chǎn)菌的菌種選育…………………………………………………………3
 1.4 本文的研究目標(biāo)和思路 …………………………………………………………….7
2 實驗部分 …………………………………………………………………………………….8
    2.1 材料  …………………………………………………………………………………8
 2.2 實驗儀器 …………………………………………………………………………….9
 2.3 方法 ………………………………………………………………………………….9
3結(jié)果與討論 …………………………………………………………………………………15
 3.1 菌株篩選方法的建立 ………………………………………………………………15
 3.2 突變體原生質(zhì)體的制備條件研究 …………………………………………………17
 3.3 基因組重排育種 ……………………………………………………………………19
4 總結(jié)與展望………………………………………………………………………………….22
致謝  ………………………………………………………………………………………….23
參考文獻(xiàn)……………………………………………………………………………………….24

摘要：洛伐他汀（lovastatin）是土曲霉（Aspergillus terreus）所產(chǎn)生的一種降血脂物質(zhì)，它通過抑制體內(nèi)膽固醇生物合成的關(guān)鍵酶HMG—CoA還原酶的活性而發(fā)揮作用。目前土曲霉菌種的發(fā)酵產(chǎn)量普遍偏低，本文將一種較新的育種方式基因組重排用于土曲霉菌種的選育，以提高其洛伐他汀的產(chǎn)量。初步探討了耐前體和耐自身代謝產(chǎn)物突變株的篩選方法，對土曲霉原生質(zhì)體的制備條件進(jìn)行了研究，考察了菌體菌齡、酶種類、酶濃度等對土曲霉原生質(zhì)體制備的影響。用紫外線滅活和熱滅活對原生質(zhì)體進(jìn)行了滅活并初步進(jìn)行了基因組重排實驗。經(jīng)過兩輪基因組重排實驗初步獲得了具有潛在高產(chǎn)性能的10株抗性菌株（其中耐乙酸鈉前體的抗性菌株6株，耐Lovastatin的抗性菌株4株）。
 
 
關(guān)鍵詞: 土曲霉；洛伐他汀；紫外誘變；化學(xué)誘變；基因組重排
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