Mathematical modelling approach for concentration and productivity enhancement of 1,3-propanediol using Clostridium diolis

1,3-Propanediol (1,3-PD) is an organic compound of immense importance particularly for polycondensation reactions to synthesise polyesters, polyethers and polyurethanes. Batch cultivation of obligate anaerobe Clostridum diolis DSM15410 for 1,3-PD production using statistically optimised medium was attempted in the present investigation. A mathematical model for the description of batch 1,3-PD production kinetics was then proposed which also incorporated substrate/product inhibition data. The kinetic parameters of the model were identified by non-linear regression technique using batch experimental data. The developed model adequately described the experimental data to the extent of 99% accuracy as tested by statistical validity test. The batch model was then extrapolated to fed-batch cultivation primarily to identify fresh nutrient feeding strategies (off-line on the computer) for enhanced production of 1,3-PD. Experimental implementation of one such fed-batch fermentation strategy involving constant feed rate and subsequent comparison of the observed kinetics with model simulation further established the accuracy of the developed model. A 1,3-PD concentration of 61.2 g/L with a productivity of 1.02 g/L/h of 1,3-PD was obtained in this mathematical-model guided fed-batch fermentation which is the highest 1,3-PD concentration ever reported in literature using this strain.

► Application of mathematical modelling for optimization of 1,3-PD production has been attempted. ► Batch mathematical model for 1,3-PD production has been proposed. ► Model parameters identified by non-linear regression technique using original batch experimental data. ► Proposed model extrapolated to fed-batch for enhanced 1,3-PD production. ► Highest 1,3-PD concentration ever reported in literature achieved using model-based fed-batch cultivation.