title: Photodynamic Inactivation of E. coli PTCC 1276 Using Light Emitting Diodes: Application of Rose Bengal and Methylene Blue as Two Simple Models.
abstract: The lack of a comparative study about potential of high-power light emitting diodes (LEDs) for photodynamic inactivation (PDI) of pathogenic microorganisms has remained as a challenging issue for researchers. Therefore, the aim of this study is to fill this gap through introduction of an efficient model for in vitro PDI in an aqueous medium. For this purpose, two individual 30 mW/cm2irradiation systems were designed using suitable sets of green and red LEDs. At another work, Methylene blue (MB) and Rose bengal (RB) as two simple models in the range of 5-150 μM were used in order to compare PDI of E. coli PTCC 1276 using red and green LED systems. Our results showed that a first-order mathematical model has the strength to describe the temporal variation of survival curves. Based on our results, when concentration of photosensitizer increased, the rate of inactivation for RB increased while MB depicted a maximum rate value at 25 μM. In a comparative study, optimum inactivation of E. coli PTCC 1276 obtained during 2- and 10-min irradiation of the LED systems using RB and MB at 150 and 25 μM, respectively. With regard to lower value of inactivation time and higher rate of inactivation for RB, use of simultaneous green high-power LEDs and RB is proposed as an efficient approach for PDI of pathogenic bacteria in future industrial applications.
authors.affiliation: Department of Physics, Babol Noshirvani University of Technology, Babol, Iran. kariminezhad@nit.ac.ir.
authors.forename: Hasan
authors.initials: H
authors.lastname: Kariminezhad
authors.affiliation: Faculty of Chemical Engineering, Babol Noshirvani University of Technology, Babol, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Amani
authors.affiliation: Department of Physics, Babol Noshirvani University of Technology, Babol, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Khanbabaie
authors.affiliation: Department of Physics, Babol Noshirvani University of Technology, Babol, Iran.
authors.forename: Mahbobeh
authors.initials: M
authors.lastname: Biglarnia
mesh_terms: D004203:Disinfection / Q000379:methods*; D004926:Escherichia coli / Q000254:growth & development*; D008027:Light; D008751:Methylene Blue / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects / Q000528:radiation effects; D012395:Rose Bengal / Q000494:pharmacology*
chemical_list: D012395:Rose Bengal; D008751:Methylene Blue
keywords: E. Coli; Light emitting diodes; Methylene blue; Photodynamic inactivation; Rose bengal