Inhibition by nisin of K+ uptake in a sensitivePediococcus sp. strain

Summary A nisin-sensitive strain ofPediococcus sp possessed an uptake system for K⁺ which was apparently dependent on metabolic energy and ATPase activity. K⁺ uptake rate was dependent on the glucose and K⁺ concentrations and showed approximately Michaelis-Menten kinetics with respect to both of these variables with K_t values of 1.2 mM and 599 μM respectively. The presence of nisin inhibited K⁺ uptake with the percentage inhibition proportional to the nisin activity,. Total inhibition occurred at between 4.5 and 5.0 IU ml⁻¹ and the MIC was approximately 0.6 IU ml⁻¹.