响应面法优化嗜热厌氧代谢工程菌发酵产乙醇的培养基

Optimization of culture mediumfor ethanol production of Thermoanaerobacterium aotearoense engineering strain by response surface methodology

利用响应面法优化嗜热厌氧代谢工程菌产乙醇的培养基,在单因素实验基础上,采用Plackett-Burman设计对影响嗜热厌氧代谢工程菌发酵产乙醇的重要培养基组分进行了筛选,确定主要影响因子为葡萄糖、木糖和酵母提取物。再用最陡爬坡实验逼近最大响应区域。最后用中心组合设计和响应面分析法,确定了主要影响因子的浓度。优化后的培养基组成为葡萄糖13.07g/L,木糖9.58g/L,酵母提取物3.78g/L,其他组分浓度同MTC培养基,不添加一水半胱氨酸盐酸盐和二盐酸吡哆氨。在此培养基条件下,乙醇产量和乙醇得率分别为(6.102±0.21)g/L和(0.38±0.012)g/g,是优化前产量的1.46倍。

The fermentation medium for ethanol production of an anaerobic thermophilic aotearoense engineenng strain was optimized by response surface methodology. Based on single factor tests, Plackett-Burman design was applied to screen key components in medium for ethanol production. Then, the steepest ascent method was adopted to determine the maximum points. Finally, the concentrations of key components were confirmed by central composite design and response surface methodology. It is showed that glucose, xylose and yeast extract were key components. The optimized medium consisted of 13.07g/L glucose, 9. 58g/L xylose, 3.78g/L yeast extract, and other components without cysteine monohydrate and ammonia pyridoxine hydrochloride at the same concentrations as MTC mediurrr In optimized medium, the ethanol productivity and ethanol yield were （6. 102 ± 0. 21 ）g/L and （0. 38 ± 0. 012）g/g respectively. The productivity was 1.46 times of that in original mediurm .