高产虾青素红法夫酵母菌株的选育和发酵参数优化
Screening and fermentation optimization of a high-yield-astaxanthin-producing Phaffia rhodozyma
-
摘要: 目的:选育出高产、稳产虾青素的红法夫酵母菌株,并对培养基进行参数优化。方法:以红法夫酵母（P.Rhodozyma 02）为出发菌株,分别进行紫外-氯化锂（UV-Li Cl）和60Co-γ诱变,从中筛选出高产虾青素的突变株作为基因组重排育种的出发菌株;经过五轮原生质体融合,筛选得到的基因组重排最优菌株。通过富含虾青素合成前体的天然促进剂的添加及对发酵培养基的参数优化,得到最佳培养基条件。结果:最终筛选得到高产、稳产虾青素的融合菌株F5-9,在此基础上优化得到最佳培养基参数条件为葡萄糖30.0 g/L,蛋白胨3.0 g/L,酵母浸出粉7.0 g/L,（NH4）2SO45.0 g/L,Mg SO4·7H2O 2.75 g/L,KH2PO41.5 g/L,Ca Cl2·2H2O 0.2 g/L,胡萝卜汁150 mg/L,最终虾青素的产量高达（83.39±1.03）mg/L,是原始出发菌株的17.56倍。结论:采用传统诱变和基因组重排技术,能显著提高虾青素产量,培养基中添加虾青素前体物质胡萝卜汁能进一步促进虾青素产量的提高。Abstract: Objective: To screen out a high- yield- astaxanthin- producing Phaffia rhodozyma and optimize the culture medium conditions.Method: Phaffia rhodozyma strain( P.rhodozyma 02) was used as original strain treated with UV- Li Cl and60Co- γ mutagenesis respectively.Mutant strains with higher astaxanthin productivity were screened out and used as the starting strains for genome shuffling. After 5 rounds of protoplast fusion,obtained the best recombinant with further high yield of astaxanthin.The optimum culture medium conditions was obtained by adding natural promoter rich in synthetic precursor of astaxanthin to the medium and optimizing the parameter of culture medium.Result: a high- yield- astaxanthin- producing recombinant F5- 9 was obtained and the optimum culture medium conditions were: glucose 30.0 g / L,peptone 3.0 g / L,yeast extract powder 7.0 g / L,( NH4)_2SO45.0 g / L,Mg SO4·7H2O 2.75 g / L,KH2PO4 1.5 g / L,Ca Cl2·2H2O 0.2 g / L,carrot juice 150 mg / L. Eventually the astaxanthin production reached at( 83.39 ± 1.03) mg / L,which was 17.56 times than the original strain. Conclusion: The traditional mutation and genome shuffling can significantly improve the yield of astaxanthin and there is room for further improvement in the yield of astaxanthin by adding natural promoter rich in synthetic precursor of astaxanthin carrot juice into culture medium.
下载: