Abstract. The elemental composition, the surface morphology and the sorption properties of glauconite from the Beloozerskoye deposit in Saratov Region were investigated. The nanocomposites based on glauconite as a matrix with doxycycline and tetracycline were synthesised. The antibacterial activity of the obtained composites against Staphylococcus aureus was studies.

Glauconite, a natural aluminosilicate, exhibits good sorption properties, is an affordable, cheap material, and has the prospect of being used in construction, ecology, medicine, cosmetology, animal husbandry, poultry farming, agriculture, etc. An urgent task is to study the sorption activity of glauconite in the Beloozersky deposit in the Saratov region in relation to biologically active substances for the creation of antimicrobial composites. The elemental composition and surface morphology of glauconite grains are determined. The sorption capacity of glauconite with respect to the pharmaceutical preparation rivanol based on acridine dye and the degree of its extraction from aqueous solutions were determined by spectrophotometry. A composite was obtained by sorption immobilization and analyzed for antimicrobial activity in relation to the standard strains of Staphylococcus aureus ATCC 6538 P and Escherichia coli ATCC 25922. An improvement in the antimicrobial properties of the immobilized preparation was revealed in comparison with an aqueous solution. The best effect of the composite in relation to Staphylococcus aureus ATCC 6538 P was determined compared to Escherichia coli ATCC 25922. The results of these studies can find practical application in veterinary medicine, poultry farming, agriculture, medicine, etc.