发酵优化绿针假单胞菌GP72-ND3ΔphzO高产吩嗪-1-羧酸

Enhancement of phenazine-1-carboxylic acid production for Pseudomonas chlororaphis GP72-ND3ΔphzO by fermentation optimization

对绿针假单胞菌GP72-ND3ΔphzO的发酵条件进行优化并在5 L反应器中进行放大培养。在摇瓶水平通过单因素实验、正交实验、最陡爬坡实验和中心组合设计实验,优化得到最佳培养基组成为甘油49.55 g/L、大豆蛋白胨37.34 g/L、KCl 1.5 g/L、MgSO_(4)0.75 g/L、K 2 HPO_(4)0.225 g/L,发酵60 h后吩嗪-1-羧酸(phenazine-1-carboxylic acid,PCA)的最大产量为(6.01±0.17)g/L,是优化前的2.6倍。在1 L反应器中优化发酵pH,当培养过程pH值维持在6.8时,PCA的产量最高,为(7.16±0.04)g/L,是优化前的1.2倍。在最优培养基和pH条件下,对菌株在5 L反应器中进行放大培养,发酵60 h后PCA的最大产量为(6.84±0.53)g/L。研究为提高PCA的生物合成速率和工业化应用提供支持。

The fermentation conditions of this strain were optimized and scaled up in a 5 L bioreactor.First,through single factor experiment,orthogonal experiment,steepest climbing experiment and central composite design experiment at the shake flask level,the optimal medium composition was obtained as 49.55 g/L glycerol,37.34 g/L soy peptone,1.5 g/L KCl,0.75 g/L MgSO_(4) and0.225 g/L K 2 HPO_(4),and the maximum production of phenazine-1-carboxylic acid(PCA)after 60 h fermentation was(6.01±0.17)g/L,which was 2.6 times as that before optimization.Then,the fermentation pH was optimized in 1 L bioreactors.When the pH was maintained at 6.8 during the culture process,the PCA production was the highest at(7.16±0.04)g/L,which was 1.2 times as that before optimization.Finally,under the optimal medium and pH conditions,the strain was scaled up cultured in 5 L bioreactors,and the maximum PCA production after 60 h of fermentation was(6.84±0.53)g/L.This study provided support for improving the production and industrial application of PCA.