A KINETIC-MODEL OF GROWTH AND PRODUCT FORMATION OF THE ANAEROBIC MICROORGANISM THERMOANAEROBACTER-THERMOHYDROSULFURICUS

A model is developed to describe the growth, product formation and enz yme synthesis of the microorganism Thermoanaerobacter thermohydrosulfu ricus. It differentiates between extracellular enzymatic starch degrad ation and the microorganism's constant specific growth rate, combined with the ingestion of maltose and maltotriose (the products of starch cleavage). The formation of growth dependent products like ethanol, ac etate and the synthesis of the cell-associated enzyme, amylopullulanas e, are formulated with constant yield coefficients. In contrast, both the non-growth dependent product lactate, and extracellular enzyme act ivity are linked to an intracellular substrate concentration. Most of the parameters used in the model are evaluated from batch culture or l iterature. The calculated results are compared with experimental data.