"MATHEMATICAL AND EXPERIMENTAL MODELING OF BIOLOGICAL EVOLUTION BY THE EXAMPLE OF RECOMBINANT BACTERIA AT CONTINUOUS CULTIVATION"
MATHEMATICAL AND EXPERIMENTAL MODELING OF BIOLOGICAL EVOLUTION BY THE EXAMPLE OF RECOMBINANT BACTERIA AT CONTINUOUS CULTIVATION Brilkov А.V., Loginov I.A., Morozova E.V., Plotnikov A.V. Krasnoyarsk State University, Institute of Biophysics SB RAS, Krasnoyarsk, 660036, Russia; phone: (3912)494455; fax: (3912)433400; e-mail: Continuous cultivation is analogous to the majority of natural situations: chemostat is similar to the situations of growth limitation by the deficiency of nutrient materials, elements and microelements; turbidostat corresponds with the conditions of maximum possible growth at limitation of population density. From the point of view of open systems functioning chemostat and turbidostat are thermodynamic systems able to maintain stable stationary state. At that, according to M. Eigen classification, chemostat conforms to the constant flows case, turbidostat – to the constant organization case (or constant reacting forces). Thus, experimentalists possess open systems of two major types of evolution both for biology and thermodynamics. If evolutionary changes or transfer from one steady state to another in the result of changing qualitative properties of the system (e.g. after the processes of mutation or selection) take place in such systems, the main characteristics of these genetic reorganizations in populations or evolution steps can be measured without losing the community of approach from the point of view of both biology and physics. By now this has not been realized from the point of view of methodology, though a lot of data on the work of both types of “evolutionary machines” has been collected. In our experiments we used the Escherichia coli strains, containing in plasmids the cloned genes of marine photobacteria bioluminescence and genes of green fluorescent protein (GFP), which expression level can be easily changed and controlled. In spite of the apparent kinetic diversity of evolutionary transfers in two types of open systems, the general mechanisms characterizing the increase of used energy flow by bacterial populations can be revealed at their study. According to the energy approach, at spontaneous transfer from one steady state to another (e.g. in the process of microevolution), heat dissipation characterizing the rate of enthropy growth should increase rather then decrease or maintain steady as М. Eigen, G. Nikolis and I. Prigozhin believed. The results of our observations of experimental evolution of recombinant bacterial strains require further development of thermodynamic theory of open biological systems and further study of general mechanisms of biological evolution.