Isolation of lactobacillus-phage and its biological characters

Abstract

On the materials gathered from sewages, salivas, dental plaques, and feces of sucklings which may contain lactobucillus, isolation of phage was done. A phage “N-1” was isolated from a material of the sewage.
N-1 phage should have biological characters as followed when examined with L. casei, strain L-10 in L-broth: adsorption rate 73 % at 37°C for 10 minutes, latent period 150 minutes, average but size 46 per cell.
Plaque formation of N-1 phage disturbed by addition of citrate-ion to L-A media as formed less than 1/5 of plaque number of the control. Addition of Ca-ion is essential to have better efficiency of plating.
Survival of N-1 phage in L-broth should decreased to less than 0.1 per cent at 60°C for 5 minutes. Of 40 lactobacillus strains, sensitivity were examined against N-1 phage and J-1 phage which was donated from the Yakuruto Institute. A few strains were detected as sensitive ones against either one of N-1 or J-1 phages respectively.