A new method studying the kinetics of L-lactic acid production by pellets Rhizopus oryzae in semi-continuous fermentation

作者：Wu, Xuefeng^*; Jiang, Shaotong; Zhang, Min; Luo, Shuizhong; Li, Xingjiang; Pan, Lijun; Zheng, Zhi; Liu, Mo

来源：Annals of Microbiology, 2015, 65(3): 1473-1480.

DOI：10.1007/s13213-014-0986-9

• L-Lactic acid
• Kinetics
• Rhizopus oryzae
• Semi-continuous fermentation

L-Lactic acid production by Rhizopus oryzae in a semi-continuous fermentation system has been recognized as a promising technology. We studied L-lactic acid production in ten batches of semi-continuous fermentation by R. oryzae using a 7-L stirred fermentor and found that the kinetics of the system was in good agreement with the logistic and Luedeking-Piret model equations. In particular, in order to mathematically calculate the actual specific growth rate in each repeated batch, we assumed that the new biomass was "zero" at the beginning of each repeated batch, and the same method was used to calculate the parameters of the product formation kinetic. The biomass remaining from the previous batches played an important role in the L-lactic acid production in each repeated batch. During the repeated fermentation, the values of delta (the efficiency of the reused biomass maintained in the former batch for producing L-lactic acid (%)) all exceeded 90 %, but the values of Q(Pm) (maximum L-lactic acid production rate) decreased gradually, possibly due to the breaking-down and autolysis of the biomass concomitant with the growth of new fungi, which led to the reduction in the maximum specific growth rate (mu(m)).

• 出版日期2015-9
• 单位合肥工业大学