DYE 10-N-NONYL ACRIDINE ORANGE AS A FLUORESCENT INDICATOR OF THE ACTION OF THE ANTISEPTIC OCTENIDINE ON THE MEMBRANES OF RHODOBACTER SPHAEROIDES CHROMATOPHORES

Abstract

Increasing volumes of produced antiseptics and disinfectants, which are widely used in medicine, veterinary medicine, the food industry and everyday life, can create a serious environmental problem after use. Previously, under the infl uence of micromolar concentrations of a number of antiseptics, we identifi ed disturbances in the functioning of photosynthetic membranes and phototransforming pigment-protein complexes isolated from them in various representatives of photosynthetic organisms. In this work, to determine the sensitivity of photosynthetic membranes to the action of the cationic antiseptic octenidine, we used chromatophores of the purple nonsulfur bacteria Rhodobacter sphaeroides, labeled with the fluorescent dye 10-N-nonylacridine orange (NAO). It was shown that the binding of NAO to chromatophores is accompanied by a shift in the dye emission maximum from 525 to 640 nm. The “red” fluorescence of NAO associated with chromatophores turned out to be sensitive to the effect of increasing concentrations of octenidine on photosynthetic membranes. We have found antiseptic concentrations which led to the degradation of chromatophore structures and change in the NAO aggregative state. It can be detected by an increase of “green” fluorescence in the emission spectra of the dye. The properties of NAO as a fluorescent indicator of the functional state of photosynthetic membranes and possible changes that can occur in such systems under the influence of a cationic antiseptic are discussed.