National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, PO Box 353, Beijing 100190, People's Republic of China.
Bioprocess Biosyst Eng. 2011 Jan;34(1):67-73. doi: 10.1007/s00449-010-0447-1. Epub 2010 Jul 6.
Lactic acid production by repeated fed-batch fermentation using free and immobilized cells of Lactobacillus lactis-11 in a packed bed-stirred fermentor (PBSF) system filled with different support materials including ceramic beads, macro-activated carbon cylinders and glass fiber balls was investigated. The results showed that the optimal support materials were the ceramic beads with diameters of 1-2 mm. Compared with the free cell fermentation system, lactic acid production and volumetric productivity in the PBSF system increased by 16.6 and 12.5%, respectively. Though the concentration of free cells decreased sharply, lactic acid production remained stable in five consecutive fed-batch runs using the PBSF system. pH gradients, immobilized cell concentration and mass diffusion in the packed bed were all affected by the recirculation rate of the culture broth. Maximum lactic acid production, productivity and yield occurred at a recirculation rate of 50 mL min(-1).
利用填充床搅拌发酵罐（PBSF）系统，使用游离和固定化的乳杆菌-11 细胞，在填充了不同支撑材料的系统中进行分批补料发酵，研究了乳酸的生产情况。这些支撑材料包括陶瓷珠、大孔活性炭柱和玻璃纤维球。结果表明，最佳的支撑材料是直径为 1-2 毫米的陶瓷珠。与游离细胞发酵系统相比，PBSF 系统中的乳酸产量和比生产速率分别提高了 16.6%和 12.5%。尽管游离细胞的浓度急剧下降，但在使用 PBSF 系统的五次连续分批补料发酵中，乳酸的产量仍然保持稳定。pH 梯度、固定化细胞浓度和质量在填充床中的扩散都受到培养液再循环率的影响。在再循环率为 50 mL min(-1)时，乳酸的最大产量、生产速率和产率最高。
