Modification of the Protein Structures of Gram-Positive and Gram-Negative Bacteria by Hydroxyl Radicals

The luminescence of gram-positive (Staphylococcus aureus) and gram-negative (Leminorella richardii) bacteria was studied in the excitation wavelength range of 265–295 nm before and after interaction with OH• radicals. For the gram-negative bacteria, luminescence was recorded at a wavelength of 330 nm. For the gram-positive bacteria, in addition to the peak at 330 nm, a peak at a wavelength of 303 nm was visible. The fluorescence spectra of bacteria in the excitation wavelength range of 265–295 nm made it possible to distinguish between gram-positive and gram-negative bacteria. After reaction with OH• radicals at a dose greater than 240 J/(10 mL), a peak of tyrosine at 303 nm was observed in the luminescence of both bacteria.