Effect of liposome-encapsulated nisin on insoluble glucan synthesis by Streptococcus mutans. Exponentially proliferating cultures of S. mutans 10449 (turbidity of 0.02 at 600 nm) were incubated in Todd Hewitt Broth containing 0.25% sucrose at 37°C for 3.75 h in the presence of liposome-encapsulated nisin at concentrations equivalent to that of naked nisin, or naked nisin alone. Symbols indicate the lipid formulations of liposomes and controls. * P < 0.05 compared with the control liposome nisin-loaded DPPC. Values represent the mean of triplicate replications and the bars represent the standard deviation of sample means.