[Adsorption of spin-labeled flocculants on E. coli cells]

The interaction of intact E. coli cells with polymeric flocculants polyethylenimine and dextran was being studied by spin-labelling. The nitroxyl groups of spin-labelled polymers are reduced during formation of the adsorption layer on the cell surface. Some peculiarities of redox reactions between polymer macroradicals and units of the bacterial electron-transport chain were studied depending of temperature and flocculation regime. The course of the reduction of spin-labelled polymer radicals and characteristics of EPR spectra of the flocculant give evidence on the formation of a loose polymeric layer on the surface of E. coli cells.