The dynamical analogy between microbial growth on mixtures of substrates and population growth of competing species.
There is a similarity between the metabolic dynamics of a microbial species growing on a mixture of two substrates and the dynamics of growth of two competing populations. Specifically, the enzymes catalyzing the uptake and catabolism of substrates exhibit phenomena analogous to extinction and coexistence."Extinction" of the enzymes associated with one of the substrates results in sequential utilization of the substrates (diauxie) (Monod, 1942). "Coexistence" of the enzymes associated with the substrates results in simultaneous utilization of the substrates (Egli, 1995). Here, we formulate a simple model that shows the basis for this dynamical similarity: The equations describing the evolution of the enzyme levels are dynamical analogs of the Lotka-Volterra model for two competing species. The analogy suggests ways of capturing the experimentally observed preculture-dependent growth patterns, i.e., growth patterns that vary depending on the physiological state of the preculture.
Narang
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Amoco Research Center, H-7, 150 West Warrenville Road, Naperville, Illinois 60563, USA. anarang@amoco.com
D001419:Bacteria / Q000254:growth & development*; D018533:Biomass; D004798:Enzymes / Q000378:metabolism; D007700:Kinetics; D008433:Mathematics; D008954:Models, Biological; D013045:Species Specificity
D004798:Enzymes