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 ofHydrogenophaga 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, μmax 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.   Key words: Kinetic model, polyhydroxyalkanoates, Hydrogenophaga pseudoflava,logistic model, Monod, biopolymer.