Alkyl Esters of p-Hydroxybenzoic Acid Induction of Premature Lysis of Phage-infected Lactobacillus casei

Abstract

During the course of investigations on the effect of antiseptics for foodstuff on a Lactobacillus casei-phage J 1 system, we have found that alkyl esters (n-butyl, isobutyl, n-propyl, isopropyl and ethyl) of p-hydroxybenzoic acid are new lysing agents for phage-infected cells. Unlike streptomycin, a known lysing agent in this system, the esters induced premature lysis of infected cells when they were added during the whole of the latent period. The infecting phage was lost and no new phage was produced. The lysing activity of the esters increased with an increase in the number of carbon atoms in the alkyl chain: butyl>propyl>ethyl. Free p-hydroxybenzoic acid, not esterified, had no lysing activity. At the available concentrations, the esters inhibited the growth of uninfected cells, but did not cause their lysis. The lytic reaction induced with the esters is not due to phage-endolysin, but may be caused by the increase in the permeability of the cytoplasmic membrane with phage infection. Esters of p-hydroxybenzoic acid could be used not only to determine the intracellular phage (free phage was not inactivated under the conditions of lysis induction), but also to elucidate the intracellular events during the eclipse period. The effect of esters of p-hydroxybenzoic acid on a L. casei-phage J 1 system was also described. © 1973, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.