Resistance of two temperate Lactobacillus paracasei bacteriophages to high pressure homogenization, thermal treatments and chemical biocides of industrial application

Food Microbiol. 2012 Feb;29(1):99-104. doi: 10.1016/ Epub 2011 Sep 14.


Temperate bacteriophages ф iLp84 and ф iLp1308, previously isolated from mitomycin C-induction of Lactobacillus paracasei strains 84 and CNRZ1308, respectively, were tested for their resistance to several physical and chemical treatments applied in dairy industry. Long-term survival at 4 °C, -20 °C and -80 °C, resistance to either thermal treatments of 63 °C, 72 °C and 90 °C, high pressure homogenization (HPH, 100 MPa) or classic (ethanol, sodium hypochlorite and peracetic acid) and new commercial sanitizers, namely A (quaternary ammonium chloride), B (hydrogen peroxide, peracetic acid and peroctanoic acid), C (alkaline chloride foam), D (p-toluensulfonchloroamide, sodium salt) and E (ethoxylated nonylphenol and phosphoric acid), were determined. Phages were almost completely inactivated after eight months of storage at 25 °C, but viability was not affected at 4 °C, -20 °C or -80 °C. Both phages tolerated well HPH treatments. Phage iLp1308 showed higher thermal resistance than ф iLp84, but neither resisted 90 °C for 2 min. Best chemical inactivation was accomplished using peracetic acid or biocides A, C and E, whereas biocides B and D were completely ineffective. These results help to improve selection of chemical agents and physical treatments to effectively fight against phage infections in dairy plants.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteriophages / chemistry*
  • Bacteriophages / drug effects*
  • Bacteriophages / growth & development
  • Disinfectants / pharmacology*
  • Food Contamination / prevention & control
  • Food Microbiology
  • Hot Temperature
  • Lactobacillus / virology*
  • Pressure
  • Sterilization / methods*
  • Virus Inactivation / drug effects


  • Disinfectants