Antimicrobial Efficiency of Photoactivated Chlorophyllin-Chitosan Complex

Abstract

The aim of this study was to assess the antimicrobial efficiency of a photoactivated chlorophyllin–chitozan complex against the food pathogen Salmonella enterica. Salmonella enterica was used for experiments. Aliquots of bacterial suspensions (~1×10 7 CFU/ml in 0.9 % NaCl) with 0.001 % chlorophyllin–0.1 % chitosan complex (Chl–CHS) were incubated in the dark at 37 C for 0–120 min. For the photoactivation, the samples were exposed to light (λ = 405 nm) for 30 min (light dose 17.3 J/cm 2). Microbial viability was evaluated by the spread plate method. The Chl-based photosensitization treatment reduced the bacterial population by 1.39 log. An extremely high antibacterial efficiency was demonstrated after photoactivation of the Chl–CHS complex (7.3 log reduction of microbial population). Experimental data support the idea that a photoactivated CHS–Chl complex in a slightly acidic environment can be a useful tool against the gram-negative bacteria S. enterica.