【摘要】 为了提高乳链菌肽(Nisin)的生产效率,采用嗜热乳链球菌6032ACA微囊细胞发酵生产乳链菌肽(Nisin).比较微囊化细胞与游离细胞的发酵效果,并通过电镜对不同时期的微囊壁结构进行观察,确定微囊的稳定性.在单次单因素实验的基础上,根据Box-Behnken中心组和设计原理,采用响应面法优化发酵条件.实验结果表明微囊细胞发酵的效价高于游离细胞,在一定时间内,微囊细胞发酵稳定性好,随着时间的延长,微囊破裂,效价降低.实验确定的最适条件为:pH 6.1,培养温度28.7℃,发酵时间20h,在此条件下得到Nisin的效价为5 460.00IU/mL.经实验验证实验值与理论预测值拟合良好,证明通过响应面分析法对嗜热乳链球菌6032ACA液芯微囊发酵生产Nisin发酵条件的优化是有效的.更多还原

【Abstract】 In order to enhance the production efficiency of Nisin,which was fermentation produced by Streptococcus Thermophilus 6032 ACA liquid core microcapsule cells,comparison fermentation effect of free cells and microcapsule cells,the different periods of the microcapsule cells wall were observed through the electron microscope,and the stability of the microcapsule cells were also ascertained.According to the Box-Behnken group and design principle based on single factor experiment,the fermentation conditions of producing Nisin by ACA liquid core microcapsule of Streptococcus Thermophilus 6032 were optimized using response surface methodology.These experimental results showed that the fermentation titer of microcapsule cell was more higher than that of free cell,the fermentation stability was good in a certain period of time.With the extension of time,the microcapsule was destroyed,resulting to lower titer.The results showed that the optimal fermentation conditions were as follows:pH 6.1,the culture temperature of 28.7 ℃,the fermentation time of 20 h.Under these conditions,the titer unit of Nisin was 5 460.00IU/mL,in which the experimental values of the titer of Nisin were closed to predicted value.These showed that it is effective for optimizing fermentation conditions of the ACA liquid core microcapsule of Streptococcus Thermophilus6032 producing Nisin using response surface methodology.更多还原