采用无机盐培养基毕赤酵母发酵生产重组人溶菌酶,以人工配置的标准溶液作为建模集,利用ATRFTIR结合PLS建立甘油和甲醇的预测模型,模型具有良好的稳定性和预测性,甘油预测模型的SEC和SEV分别为0.171和0.532 g/L,甲醇预测模型的SEC和SEV分别为0.129和0.248 g/L。在5 L发酵罐中运用建立的模型预测发酵液中甘油和甲醇的浓度,预测标准误差(SEP)分别为1.09和0.86 g/L,表明模型稳定,能有效指导实际生产。比较5 L发酵罐中分别采用FTIR调控和溶氧(DO-stat)调控甲醇浓度下的比生长速率(μ)和比生产速率(Qp),结果表明,FTIR调控下比生长速率和比生产速率均高于溶氧(DO-stat)调控。

Mid-infrared FTIR spectroscopy is an efficient tool for the monitoring of bioprocesses. The use of Fourier transform mid-infrared spectroscopy( FTIR) combined with PLS to predict the concentrations of glycerol and methanol in fed-batch cultivations of Pichia pastoris in a chemical medium was investigated by using the synthetic solutions as calibration set. Generally,all models were robust and performed well,the calibration model allowed standard errors of calibration( SEC) and standard errors of validation( SEV) for glycerol and methanol concentrations of 0. 171,0. 532,0. 129 and 0. 248 g/L,respectively. The results from 5 L Fed-batch experiments showed that FTIR data had a good agreement with control data,with standard error of prediction( SEP) of 1. 09 and 0. 86 g/L,respectively. Specific growth rate and specific production rate were compared between FTIR and DO-stat to control methanol concentration. Results showed that FTIR could limit the methanol concentration under 2%,which could maintain a higher specific growth rate and specific production rate that was effective to enhance the production.