Gamma-aminobutyric acid (GABA) is a natural non-protein functional amino acid

which has potential for fermentation industrial production by

Lactobacillus brevis

. This work investigated the batch fermentation process and developed a kinetic model based on substrate restrictive model established by experimental data from L

25

(5

6

) orthogonal experiments. In this study

the OD

600

value of fermentation broth was fixed to constant after reaching its maximum because the microorganism death showed no effect on the enzyme activity of glutamate decarboxylase (GAD). As pH is one of the key parameters in fermentation process

a pH-dependent kinetic model based on radial basis function was developed to enhance the practicality of the model. Furthermore

as to decrease the deviations between the simulated curves and the experimental data

the rolling correction strategy with OD

600

values that was measured in real-time was introduced into this work to modify the model. Finally

the accuracy of the rolling corrected and pH-dependent model was validated by good fitness between the simulated curves and data of the initial ba

tch fermentation (pH 5.2). As a result

this pH-dependent kinetic model revealed that the optimal pH for biomass growth is 5.6-5.7 and for GABA production is about 5

respectively. Therefore

the developed model is practical and convenient for the instruction of GABA fermentation production

and it has instructive significance for the industrial scale.