A measure of biological robustness in microbial metabolic systems and its approximated estimation

It has long been recognized that robustness is an inherent property of all biological systems. For instance, microbes could maintain their intracellular environment in a relative stable level against the changes in the extracellular environment. We study such a phenomenon in the glycerol production by microbial continuous fermentation, in which the metabolism mechanisms are not completely known and the true metabolism system need to be identified from all possible ones. We present a quantitative index of biological robustness to measure the robustness of all candidate metabolic systems. An approximated estimation scheme for the calculation of the proposed robustness index is constructed and convergence result is presented.