Thermal, chemical, and photocatalytic inactivation of Lactobacillus plantarum bacteriophages.
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.
Briggiler Marcó
Mariángeles
M
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
De Antoni
Graciela L
GL
Reinheimer
Jorge A
JA
Quiberoni
Andrea
A
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
D003470:Culture Media; D004202:Disinfectants; D012973:Sodium Hypochlorite; D010463:Peracetic Acid