Energetics and Dynamics of self-propelled microorganisms in aqueous media

C.A. CONDAT; M. DI SALVO; G.J. SIBONA

La Falda, Cordoba

Simposio; 3º Simposio de Mecánica Estadística, Teoría de la Información y Biofísica.; 2010

Microorganism motion is usually described in a geometric fashion, without considering its dependence on the organism´s energy budget. We will present a formalism developed to investigate how self-propelled microorganisms may administer their resources in order to optimize space exploration. The microorganism is modelled as an active particle that allocates to motion part of the energy it absorbs from environmentally available nutrients. In the case of bacteria, it is possible to use experimental data to infer the relation between the rate of energy transfer to the flagellar motors and the instantaneous bacterial speed. The presence of two well-separated time scales justifies using a quasi-stationary approximation to obtain analytical results describing not only the stationary values of speed and stored energy, but also the time dependence of bacterial speed and its corrrelation with the available energy. The description is supplemented with computer simulations of the complete equations