Inhibition of bacterial spores and vegetative cells by glycerides

Monolaurin, monomyristin, monolinolein, and monolinolenin inhibited cell growth from Bacillus cereus T, Clostridium botulinum 62A, and Clostridium sporogenes PA3679 spores and vegetative cells. The inhibitory action increased in the order monolinolein, monomyristin, monolaurin, monolinolenin. Monopalmitin, monostearin, and monolein had a partial effect and diglycerides and triglycerides had no effect. B. cereus T spores were more sensitive to monolaurin, monomyristin, monolinolein, and monolinolenin than vegetative cells. Spores and vegetative cells of C. botulinum 62A were similarly affected by monolaurin, whereas vegetative cells were more resistant to monomyristin, monolinolein, and monolinolenin than spores. In general, C. botulinum 62A and C. sporogenes PA 3679 were more resistant than B. cereus T, except for monolinolein and monomyristin, in which Bacillus spores were more resistant than PA3679 spores. C. botulinum 62A spores were equally (monomyristin) or less resistant (monolaurin, monolinolenin) than PA3679. Monomyristin had the same activity on the three strains. Monolaurin (0.073 to 0.109 mM), monomyristin (0.331 to 0.497 mM), and monolinolenin (0.085 to 0.182 mM) affected germination and outgrowth, whereas monolinolein (0.564 to 0.848 mM) inhibited cell multiplication from B. cereus T spores. Monolaurin (0.145 to 0.182 mM) inhibited outgrowth, but monomyristin (0.331 to 0.497 mM) and monolinolenin (0.142 to 0.182 mM) affected germination of 62A spores. Cell multiplication was inhibited by monolinolein (0.564 to 0.848 mM). C. sporogenes PA3679 spore germination and outgrowth were inhibited by monomyristin (0.331 to 0.497 mM) and monolinolenin (0.142 to 0.282 mM), or monolaurin (0.182 to 0.255 mM), monomyristin (0.165 to 0.248 mM), and monolinolenin (0.085 to 0.113 mM) inhibited cell multiplication from PA3679. Starch neutralized the inhibitory activity of monolaurin, monomyristin, monolinolein, and monolinolenin against 62A spores. The starch antagonism decreased as the concentration of glyceride increased.