Phages of Lactobacillus casei/paracasei. Response to environmental factors and interaction with collection and commercial strains

MARÍA LUJÁN CAPRA; ANDREA DEL LUJÁN QUIBERONI; JORGE ALBERTO REINHEIMER

JOURNAL OF APPLIED MICROBIOLOGY

Blackwell Science

Lugar: Londres; Año: 2006 vol. 100 p. 334 - 342

1364-5072

Aim: To investigate the influence of several environmental factors on the viabilityand cell-adsorption for two Lactobacillus casei/paracasei bacteriophages(PL-1 and J-1).Methods and Results: Both phages showed a remarkably high specificity ofspecies, sharing similar host spectra. Two phages and four sensitive strains wereused to conform five phage/strain systems. Each showed a particular behaviour(burst size: ranging from 32 to 160 PFU/infective centre; burst time: 120–240 min and latent time: 5–90 min). For both phages, the viability was not significantlyaffected from pH 4 to 11 (room temperature) and from pH 5 to 10(37°C). Adsorption rates were not influenced by calcium ions, but decreasedafter the thermal inactivation of cells. Adsorption rates were high between 0and 50°C with maximum values at 30°
C and pH 6. System PL-1/Lact. paracaseiA showed noticeable differences in comparison with the others, being timesrequired to reach 90% of adsorption of 4 h and lower than 45 min, respectively.Conclusions: The data obtained in this work demonstrated that environmentalparameters can influence the viability and cell adsorption rates of Lact. casei/paracasei phages. The extent of this influence was phage dependent.Significance and Impact of the Study: This work contributes to the enlargementof the currently scarce knowledge of phages of probiotic bacteria.