Control of Bacillus subtilis Spores by Intermittent Treatment Using Heating after Carbonation in the Presence of Germinants and Bacteriostatic Agents

Abstract

We investigated the inactivation effect of intermittent treatments using carbonation under heating (CH) and second heating (HT), in the presence of germinants or monoglycerol caprate (MC10) on Bacillus subtilis spores. Intermittent treatments by CH, followed by incubation and a second HT, in the presence of germinants showed up to 2.6 log-order inactivation effects on spores. Compared with the effects of glycine, sodium benzoate, and potassium sorbate, MC10 increased the inactivation effect of CH. MC10 decreased the D value and activation energy for inactivation of the spores. Intermittent treatments with MC10, conducted by a CH, followed by HT, inactivated spores by 3.6 log-orders. CH with MC10 induced the release of dipicolinic acid (DPA) and increased the stainability of the spores by DAPI. This suggests that germination-like phenomena, during CH, were included in the inactivation effects. Spores, which survived the intermittent treatment combined with MC10, did not proliferate in a liquid medium.