响应面法优化高产虾青素菌株的发酵条件

采用析因设计法对影响红法夫酵母发酵的相关因素进行评价，发现酵母膏、初始pH 值、葡萄糖及果糖浓度对虾青素产量影响显著。利用中心组合设计及响应面分析对影响虾青素产量的关键因素做进一步的优化，得到较佳的试验点为酵母膏浓度5.6g/L、初始pH 8.5、葡萄糖与果糖浓度之比24:21(m/V)。优化后虾青素产量从5.890mg/L提高到10.900mg/L；7.5L 发酵罐中，虾青素产量可达18.300mg/L，比摇瓶培养提高了68%。

Optimization of Fermentation Conditions for Astaxanthin Production by Phaffia rhodozyma Using Response Surface Methodology

Fractional factorial design was used to evaluate effects of related factors on astaxanthin production by Phaffia rhodozyma fermentation. Based on this, central composite design combined with response surface methodology was employed for optimizing the most important affecting factors of astaxanthin production. Results showed that the factors including initial pH, yeast extract amount, concentrations of glucose and fructose exhibited the most important effects on astaxanthin yield. The optimal fermentation medium composition for high astaxanthin yield consisted of 5.6 g/L yeast, 24 g/L glucose and 21 g/L fructose with an initial pH value of 8.5. This optimization resulted in an increase of astaxanthin yield from 10900 to 5890 μg/L. Moreover, enlarged fermentation in a 7.5 L fermentor gave an astaxanthin yield as high as 18300 μg/L with an enhancement of 68% when compared with shake flask fermentation.