Biotechnology and Bioengineering, Vol.69, No.3, 292-300, 2000
Growth and sporulation stoichiometry and kinetics of Coniothyrium minitans on agar media
Coniothyrium minitans was cultivated on agar media with different concentrations of starch, urea, and trace elements. By means of elemental balances, the stoichiometry of growth and sporulation was established. C. minitans produced byproducts on all media, especially in the medium with high urea concentrations, where 30% of the starch was converted into byproducts. Simple empirical models were used to describe the kinetics of growth, sporulation, CO2 production, and substrate consumption on all media. Total biomass and mycelium could be described reasonably well with the logistic law. Starch, urea, and oxygen consumption and CO2 production could be described as a function of total biomass by the linear-growth model of Pirt. There were almost no differences between media for the estimates of yield coefficients and maintenance coefficients. Only at high urea concentrations were maintenance coefficients much higher. Similar to substrate consumption and CO2 production, the kinetics of sporulation could be described as a function of mycelium production with the linear-growth model. it is shown that sporulation of C. minitans is growth-associated. Based on kinetics, the process costs for producing spores are roughly calculated. In addition, it is shown that fermenter costs represent the majority of production costs.
Keywords:Coniothyrium minitans;spore production;elemental balances;kinetics;stoichiometry;solid-state cultivation