Mathematical modeling of fed-batch fermentation of Schizochytrium sp FJU-512 growth and DHA production using a shift control strategy

作者：Zhang, Mingliang; Wu, Weibin; Guo, Xiaolei; You Weichen; Qi, Feng; Jiang, Xianzhang; Huang, Jianzhong^*

来源：3 Biotech, 2018, 8(3): 162.

DOI：10.1007/s13205-018-1187-1

• Schizochytrium sp FJU-512
• Docosahexaenoic acid (DHA)
• Fed-batch
• Logistic model
• Luedeking model

To obtain high-cell-density cultures of Schizochytrium sp. FJU-512 for DHA production, two stages of fermentation strategy were used and carbon/nitrogen ratio, DO and temperature were controlled at different levels. The final dry cell weight, total lipid production and DHA yield in 15 l bioreactor reached 103.9, 37.2 and 16.0 g/l, respectively. For the further study of microbial growth and DHA production dynamics, we established a set of kinetic models for the fed-batch production of DHA by Schizochytrium sp. FJU-512 in 15 and 100 l fermenters and a compensatory parameter n was integrated into the model in order to find the optimal mathematical equations. A modified Logistic model was proposed to fit the cell growth data and the following kinetic parameters were obtained: mu(m) = 0.0525/h, X-m = 100 g/l and n = 4.1717 for the 15 l bioreactor, as well as mu(m) = 0.0382/h, Xm = 107.4371 g/l and n = 10 for the 100 l bioreactor. The Luedeking-Piret equations were utilized to model DHA production, yielding values of alpha = 0.0648 g/g and beta = 0.0014 g/g/h for the 15 l bioreactor, while the values of alpha and beta obtained for the 100 l fermentation were 0.0209 g/g and 0.0030 g/g/h. The predicted results compared with experimental data showed that the established models had a good fitting precision and were able to exactly depict the dynamic features of the DHA production process.

• 出版日期2018-3-7
• 单位福建师范大学