关键词: Lactobacillus casei Zhang 高密度发酵 中试 动力学

Abstract:

Based on lab scale （3 L） experiments, the pilot plant scale test （30 L to 150 L） of the high cell density culture of L. casei Zhang was studied toget the optimal fermentation technology for industrial production. Under optimized culture conditions, the viable count of fermented liquid was 2.9 × 10^10cfu/mL and there was no significant different between pilot plant test and lab scale test. The kinetic models of growth and glucose consumption for L. casei Zhang were constructed using origin7.5 software based on the equations of ＂logistic equation＂ and fit well with the experimental data, with an average error of less than 10%. These models could forecast the actual fermentation process. Preliminary study was carried out on the influences of centrifugation and freeze-drying processes on cells after fermentation. Although the average viable cell count of the lyophilized powder was 2.65 × 10^11 cfu/g, which could meet the requirements of the probiotics and starter cultures, only 49.97% of L. casei Zhang cells were survived from freeze drying. So it＇s necessarily to make further study on how to improve the survival rate of L. casei Zhang during freeze drying.

Key words: Lactobacillus casei Zhang, high cell density culture, pilot plant test, kinetics