Autolyse the cell in order to save it? Inducing, then blocking, autolysis as a strategy for delaying cell death in the probiotic Lactobacillus reuteri

Objective: To examine whether choline and its derivatives can be used to preserve viable cells of Lactobacillus reuteri in autolytic models. Results: A phosphate-induced autolytic model in de Man, Rogosa and Sharpe medium (MRS) was used. Viable cell counts were determined by plated on MRS-agar. Choline and hemicholinium-3 (HC-3) significantly blocked autolysis of L. reuteri at 360 mM and 4 mM, respectively. Viable cell counts corroborated these observations. Importantly, autolytically induced cells treated with choline and hemicholinium-3 were significantly more viable then even non-induced cells. Over-production of a known autolytic protein, spirosin, was not attenuated in the presence of choline and hemicholinium-3. Conclusion: Inducing autolysis and then blocking it with choline and its analogs is a promising approach for retaining the viability of L. reuteri cells.