The structure of the cell surface reflects the functional state of the bacterium as a whole. The presence of specific features of cells affects the biophysical characteristics of their surface: charge, free energy and hydrophobicity. The interaction of bacteria with biomolecules and particles is also related to these surface characteristics. The aim of our work was to study the function of F. tularensis 15 NIIEG cells under cultivation under stress using electro-optical (EO) monitoring.