透明颤菌血红蛋白的表达对酵母中麦角固醇合成的影响  

Enhanced Ergosterol Production by Recombinant Saccharomyces cerevisiae 1190 Harboring Vitreoscilla Hemoglobin Gene (vgb)

作　　者：范楠[1] 李炎[1] 周全[2] 陈国强[2] 

机构地区：[1]暨南大学食品研究与开发中心,广州510632 [2]清华大学生物科学与技术系,北京100084

出　　处：《生物工程学报》2004年第3期441-444,共4页Chinese Journal of Biotechnology

摘　　要：构建了含透明颤菌 (Vistreoscilla)血红蛋白基因vgb和酵母遗传霉素 (G4 18)抗性基因的重组质粒pVgb kan MX4 ,转化至酿酒酵母Saccharomycescerevisiae 1190中 ,经过分析 ,基因vgb在酵母细胞中得到表达。对重组菌和野生菌进行了摇瓶培养及 5L发酵罐培养的研究。在摇瓶实验中 ,重组菌的麦角固醇产量比野生菌有显著提高 ,在野生菌中的含量为 0 5 73%、而在重组菌中的产量为 1 0 7%。经过 30h发酵罐培养的实验 ,野生菌中麦角固醇含量为0 9% ,重组菌中其含量为 1 38% ,验证了摇瓶实验的结果。结果证明vgb基因有利于酵母中麦角固醇的合成。Ergosterol is a principal sterol of fungi. It is a raw material for production of vitamin D 2, hydrocortisone, progesterone and brassinolide. Synthesis of ergosterol requires molecular oxygen, and low oxygen tensions was reported to dramatically reduce ergosterol concentration. Vitreoscilla Hemoglobin Gene (vgb), a homodimeric hemoglobin gene from Gram-negative obligate aerobic bacterium Vitreoscilla, enables a higher specific cellular oxygen uptake rate, it also improves the oxygen transportation. In this study, recombinant plasmid pVgb-kanMX4 containing Vitreoscilla Hemoglobin Gene (vgb) and geneticin (G418) was constructed and transformed into Saccharomyces cerevisiae 1190 for enhanced ergosterol production. With sufficient oxygen supply, the ergosterol contents of recombinant and wild type strains grown in shake flasks were 1.07% and 0.573%, respectively. Under oxygen limitation condition, ergosterol contents in recombinant and wild type strains were reduced to 0.39% and 0.25%, respectively. In a 30 hours fermentation study conducted in a 5 liter fermentor, 15.1 g/L Cell Dry Weight (CDW) containing 1.38% ergosterol was obtained from growth of the recombinant strains; Only 14.8 g/L CDW containing 0.9% ergosterol was produced by the wild type strain. These results demonstrated that vgb played a role in enhancing ergosterol production.

关 键 词：透明颤菌血红蛋白基因 麦角固醇 酿酒酵母Saccharomyces cerevlsiae 

分 类 号：Q78[生物学—分子生物学]