Mathematical simulations of man-made microbial mixture grown on natural gas

A new mathematical model was developed and used to analyze growth kinetics of transient stages of continuous cultures leading to steady states for mixed cultures of one methylotrophic bacterium and two heterotrophic bacteria. In the model the methylotrophic species was limited by oxygen and the heterotrophic species were limited either by oxygen, maximal specific growth rate or concentration of intermediate extracellular metabolites. Simulations, based on the model, were run to determine the applicability of the model. Characteristics of the species were based on data obtained from bacteria used in industrial processes. This model is based on "ecological principles" taking into consideration various interactions among the species in a linearized form of the Monod equation. The model could account for the ability of the three species to coexist with methane as the sole carbon source at different initial conditions.