陈化籼稻谷固态发酵法生产柠檬酸的培养基优化

探讨了原料预处理、培养基组成对以陈化籼稻谷为原料、黑曲霉固态发酵法生产柠檬酸过程的影响,并通过正交试验优化了培养基组成。结果表明原料预处理采用陈化籼米粉碎度为0.5mm,每100g米粉中加水60ml后蒸煮(121℃、20min),发酵前补水40ml,无需调节pH值;固态发酵优化的培养基组成为100g米粉,添加麸皮8.5g、碳酸钙0.5g、硝酸铵0.9g,在发酵温度25℃、时间84h后柠檬酸的产量为188g/kg干物质。

Optimization of the Medium for Production of Citric Acid from Aged Long-grain Non-glutinous Rice by Solid-state Fermentation

The effect of pretreatment of raw materials and the components of substrate on production of citric acid from aged long-grain non-glutinous rice by Aspergillus niger in solid-state fermentation was investigated. Furthermore components of substrate were optimized by the orthogonal test. The optimized pretreatment’s method of raw materials was that a particle size of ground rice was 0.5mm, the 100g ground rice of adding 60ml water was steamed for 20min at 121℃ and 40ml water was supplemented into substrate and the pH of substrate was no adjustive. The optimum components of fermentative substrate are addition 8.5g bran husk, 0.5g CaCO3 and 0.9g NH4NO3 into 100g ground rice. Under these optimized conditions, the yield of citric acid was 188g/kg DM at 25℃ for 84h.