Food Engineering and Technology Department, Institute of Chemical Technology, University of Mumbai, Matunga, Mumbai 400 019, India.
J Microbiol Biotechnol. 2011 Apr;21(4):430-7.
The effects of the agitation and aeration rates on the production of serratiopeptidase (SRP) in a 5-L fermentor (working volume 2-l) were systematically investigated using Serratia marcescens NRRL B-23112. The dissolved oxygen concentration, pH, biomass, SRP yield, and maltose utilization were all continuously measured during the course of the fermentation runs. The efficiencies of the aeration and agitation were evaluated based on the volumetric mass transfer coefficient (K(L)a). The maximum SRP production of 11,580 EU/ml with a specific SRP productivity of 78.8 EU/g/h was obtained with an agitation of 400 rpm and aeration of 0.075 vvm, which was 58% higher than the shake-flask level. The KLa for the fermentation system supporting the maximum production (400 rpm, 0.075 vvm) was 11.3 h(-1). Under these fermentor optimized conditions, kinetic modeling was performed to understand the detailed course of the fermentation process. The resulting logistic and Luedeking-Piret models provided an effective description of the SRP fermentation, where the correlation coefficients for cell growth, SRP formation, and substrate consumption were 0.99, 0.94, and 0.84, respectively, revealing a good agreement between the model-predicted and experimental results. The kinetic analysis of the batch fermentation process for the production of SRP demonstrated the SRP production to be mixed growth associated.
使用粘质沙雷氏菌 NRRL B-23112，系统地研究了搅拌和通气速率对 5-L 发酵罐（工作体积 2-L）中糜蛋白酶（SRP）生产的影响。在发酵过程中，连续测量溶解氧浓度、pH 值、生物量、SRP 产率和麦芽糖利用率。根据体积传质系数（KLa）评估通气和搅拌的效率。在搅拌转速为 400 rpm 和通气量为 0.075 vvm 的条件下，获得了 11580 EU/ml 的最大 SRP 产量和 78.8 EU/g/h 的比 SRP 产率，比摇瓶水平提高了 58%。支持最大产量（400 rpm，0.075 vvm）的发酵系统的 KLa 为 11.3 h-1。在这些发酵罐优化条件下，进行了动力学建模以了解发酵过程的详细情况。所得的逻辑斯蒂和 Luedeking-Piret 模型为 SRP 发酵提供了有效的描述，其中细胞生长、SRP 形成和基质消耗的相关系数分别为 0.99、0.94 和 0.84，表明模型预测和实验结果之间具有良好的一致性。分批发酵生产 SRP 的动力学分析表明，SRP 生产与混合生长有关。
