Isolation and Characterization of Phages InfectingBacillus subtilis
Bacteriophages have been suggested as an alternative approach to reduce the amount of pathogens in various applications. Bacteriophages of various specificity and virulence were isolated as a means of controlling food-borne pathogens. We studied the interaction of bacteriophages withBacillusspecies, which are very often persistent in industrial applications such as food production due to their antibiotic resistance and spore formation. A comparative study using electron microscopy, PFGE, and SDS-PAGE as well as determination of host range, pH and temperature resistance, adsorption rate, latent time, and phage burst size was performed on three phages of theMyoviridaefamily and one phage of theSiphoviridaefamily which infectedBacillus subtilisstrains. The phages are morphologically different and characterized by icosahedral heads and contractile (SIOΦ, SUBω, and SPOσphages) or noncontractile (ARπphage) tails. The genomes of SIOΦ and SUBωare composed of 154 kb. The capsid of SIOΦ is composed of four proteins. Bacteriophages SPOσand ARπhave genome sizes of 25 kbp and 40 kbp, respectively. Both phages as well as SUBωphage have 14 proteins in their capsids. Phages SIOΦ and SPOσare resistant to high temperatures and to the acid (4.0) and alkaline (9.0 and 10.0) pH.