title: Thermal, chemical, and photocatalytic inactivation of Lactobacillus plantarum bacteriophages.
abstract: The effect of several biocides, thermal treatments, and photocatalysis on the viability of four Lactobacillus plantarum phages was investigated. Times to achieve 99% inactivation (T99) of phages at 63, 72, and 90 degrees C were evaluated in four suspension media: deMan Rogosa Sharpe broth, reconstituted skim milk, a commercial EM-glucose medium, and Tris magnesium gelatin buffer. The four phages studied were highly resistant to 63 degrees C (T99 > 45 min); however, counts < 10 PFU/ml were achieved by heating at 90 degrees C for 5 min. Higher thermal resistance at 72 degrees C was observed when reconstituted skim milk and EM-glucose medium were assayed. Peracetic acid (0.15%, vol/vol) was an effective biocide for the complete inactivation of all phages studied within 5 min of exposure. Sodium hypochlorite (800 ppm) inactivated the phages completely within 30 min. Ethanol (100%) did not destroy phage particles even after 45 min. Isopropanol did not have any effect on phage viability. Phage counts < 50 PFU/ml were obtained within 180 min of photocatalytic treatment. The results obtained in this work are important for establishing adequate methods for inactivating phages in industrial plants and laboratory environments.
authors.affiliation: Instituto de Lactología Industrial, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Científicas y Técnicas, 1o de Mayo 3250, 3000 Santa Fe, Argentina. mbriggi@fiq.unl.edu.ar
authors.forename: Mariángeles
authors.initials: M
authors.lastname: Briggiler Marcó
authors.forename: Graciela L
authors.initials: GL
authors.lastname: De Antoni
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Reinheimer
authors.forename: Andrea
authors.initials: A
authors.lastname: Quiberoni
mesh_terms: D017103:Bacillus Phages / Q000187:drug effects / Q000254:growth & development / Q000528:radiation effects; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D003470:Culture Media; D004202:Disinfectants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005514:Food Irradiation; D006358:Hot Temperature; D007700:Kinetics; D048191:Lactiplantibacillus plantarum / Q000187:drug effects / Q000528:radiation effects / Q000821:virology*; D010463:Peracetic Acid / Q000494:pharmacology; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D003470:Culture Media; D004202:Disinfectants; D012973:Sodium Hypochlorite; D010463:Peracetic Acid