Kinetic model for polyhydroxybutyrate (PHB) production by Hydrogenophaga pseudoflava and verification of growth conditions

A kinetic model that describes microbial growth, biopolymer production and substrate consumption is used to predict the performance of batch fermentation of Hydrogenophaga pseudoflava. H. pseudoflava DSMZ 1034 is useful in synthesizing polyhydroxyalkanoates (PHAs).The experimental data was also fitted with the logistic equation that can provide adequate description for PHA synthesized by H. pseudoflava. The Lineweaver-Burk plot defined biokinetic coefficients which were described by a simplified Monod’s rate model. The specific growth rates, max and the Monod constants, Ks, for various substrates such as glucose, fructose were 0.36, 0.24, h-1 and 106, 80 g/l, respectively. A good agreement was found between the experimental and the predicted values, which indicated that the model with differential equations would describe fermentation process for the PHA formation

A kinetic model for citric acid production from apple pomac by Aspergillus niger

The fermentation kinetics of citric acid by Aspergillus niger were studied in a batch system. A simple model was proposed using the logistic equation for growth, the Luedeking-Piret equation for citric acid production and Luedeking-Piret-like equation for glucose consumption. The model appeared to provide a reasonable description for each parameter during the growth phase. The production of citric acid by A. niger is growth-associated