Isolation and properties of a Pseudomonas acidovorans bacteriophage.

Abstract

SUMMARY The lytic bacteriophage ϕW-14 was isolated from sewage using Pseudomonas acidovorans no. 14 as host. The phage had an icosahedral head some 85 nm. in diameter and a contractile tail some 140 nm. long. ϕW-14 formed plaques on only a few strains of P. acidovorans. The phage gave biphasic absorption kinetics, with an adsorption constant of 1·9 × 10−9 ml./min. The latent period was 60 min. and the burst size was about 300. The burst size was dependent upon culture age. The k u.v.. for inactivation of ϕW-14 was 4·35 min.−1. P. acidovorans was shown to possess a potent photoreactivating system. The heat of inactivation of ϕW-14 was calculated to be 75,700 cal./mole. The phage gave biphasic thermal inactivation kinetics at 55° and 60° but not at 65°. The phage mutated spontaneously to a different plaque type. This mutation affected the adsorptive properties, the thermal sensitivity and the burst size of the phage.