Abee and others (1994) in a study on the mode of action of nisin Z
against L. monocytogenes (serotype Scott A) found that the addition
of nisin Z caused an immediate loss of cellular K, depolarization of
the cytoplasmic membrane, hydrolysis and partial efflux of cellular
ATP and an inhibition of respiration activity in L. monocytogenes.
We therefore hypothesize that the use of a potassium phosphate
saline instead of sodium phosphate saline might offset the loss of
intercellular K+ caused by the ability of nisin to form channels in
the cytoplasmic membrane and disrupt the PMF of Listeria cells.