Analysis of electrophysical profiles of plankton and biofilm cells on the model of <I>Azospirillum baldaniorum</I> bacteria

Biofilm formation is a widespread phenomenon in the world of microbes. They can affect human and animal health, cause damage to various industries, and at the same time can be useful in areas such as wastewater treatment or increasing the bioavailability of nutrients for plants. This actualizes the development of biofilm research methods. In this paper, an optical sensor method for indicating bacterial biofilm formation taking into account biological variability is described for the first time using the example of plant growth-stimulating rhizobacteria of the genus Azospirillum. A correlation was found between changes in the electrophysical parameters recorded by the sensor system and morphological features of bacteria from planktonic and/or biofilm cultures: the presence of motor organelles (flagella), polymorphism and ultrastructure of cellular forms. It was found that the profile of microbial cells recorded by the optical system in planktonic and biofilm forms differs significantly. When comparing cells of different strains (parent strain and its derivatives) or planktonic and biofilm bacteria, the variables recorded by the electro-optical sensor system are consistent with the changes in the micro- and ultrastructure of bacteria recorded by us using other methods. The results of the analysis of the electrophysical profiles of A. baldaniorum Sp245 can be used as a reference for identifying the specificity of the interaction of biofilm cells of this strain with various components of the root surface of the putative plant partner using an optical sensor system.