Premium
Thermal and chemical resistance of Lactobacillus casei and Lactobacillus paracasei bacteriophages
Author(s) -
Capra M.L.,
Quiberoni A.,
Reinheimer J.A.
Publication year - 2004
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1111/j.1472-765x.2004.01525.x
Subject(s) - lactobacillus paracasei , lactobacillus casei , microbiology and biotechnology , food science , lactobacillus , sodium hypochlorite , skimmed milk , lactobacillus salivarius , chemistry , bacteria , probiotic , peracetic acid , fermentation , biology , biochemistry , hydrogen peroxide , genetics , organic chemistry
Aims: The survival of two collection Lactobacillus casei and L. paracasei bacteriophages when subjected to thermal and chemical treatments was investigated. Methods and Results: Thermal resistance was evaluated by heating phage suspensions at 63, 72 and 90°C in three different media [Tris‐magnesium gelatin (TMG) buffer: 10 mmol l −1 Tris‐Cl, 10 mmol l −1 MgSO 4 and 0·1% w/v gelatin; Man Rogosa Sharpe (MRS) broth and reconstituted nonfat dry skim milk (RSM)]. A marked heat sensitivity was evident in both phages, as 15 min at 72°C was enough to completely inactivate (6 log 10 reduction) them. No clear influence was demonstrated by the suspension media. The phages also showed similar resistance to biocides. Peracetic acid and sodium hypochlorite (800 ppm) were the most effective ones, destroying the phages within 5 min. Concentrations of 75 and 100% ethanol were not suitable to inactivate phage particles even after 45 min. Isopropanol did not show an effect on phage viability. Conclusions: The data obtained in this work are important to design more effective control procedures in order to inactivate phages in dairy plants and laboratories. Significance and Impact of the Study: This work will contribute to enhance the background knowledge about phages of probiotic bacteria.