title: Adsorption of temperate phages of Lactobacillus delbrueckii strains and phage resistance linked to their cell diversity.
abstract: OBJECTIVE
  The aim of this work was to study the adsorption step of two new temperate bacteriophages (Cb1/204 and Cb1/342) of Lactobacillus delbrueckii and to isolate phage-resistant derivatives with interesting technological properties.
  
  
  RESULTS
  The effect of divalent cations, pH, temperature and cell viability on adsorption step was analysed. The Ca2+ presence was necessary for the phage Cb1/342 but not for the phage Cb1/204. Both phages showed to be stable at pH values between 3 and 8. Their adsorption rates decreased considerably at pH 8 but remained high at acid pH values. The optimum temperatures for the adsorption step were between 30 and 40°C. For the phage Cb1/342, nonviable cells adsorbed a lower quantity of phage particles in comparison with the viable ones, a fact that could be linked to disorganization of phage receptor sites and/or to the physiological cellular state. The isolation of phage-resistant derivatives with good technological properties from the sensitive strains and their relationship with the cell heterogeneity of the strains were also made.
  
  
  CONCLUSIONS
  Characterization of the adsorption step for the first temperate Lact. delbrueckii phages isolated in Argentina was made, and phage-resistant derivatives of their host strains were obtained.
authors.affiliation: Instituto de Lactologı´a Industrial (Universidad Nacional del Litoral – CONICET), Santa Fe, Argentina.
authors.forename: V
authors.initials: V
authors.lastname: Trucco
authors.forename: J
authors.initials: J
authors.lastname: Reinheimer
authors.forename: A
authors.initials: A
authors.lastname: Quiberoni
authors.forename: V B
authors.initials: VB
authors.lastname: Suárez
mesh_terms: D000327:Adsorption / Q000187:drug effects; D001435:Bacteriophages / Q000302:isolation & purification / Q000502:physiology*; D002118:Calcium / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D048668:Lactobacillus delbrueckii / Q000821:virology*; D050296:Microbial Viability; D013696:Temperature
chemical_list: D002118:Calcium