Growth Inhibition of Listeria monocytogenes by Sodium Polyphosphate as Affected by Polyvalent Metal Ions

摘要

Sodium polyphosphate (SPP, average chain length = 13) increased the lag time of L. monocytogenes Scott A (Lin) in brain-heart infusion broth (BHI). Polyvalent metal ions (1-10 mM) reversed inhibition of Lm growth by 0.5/100 SPP (nominal 3.6 mM). 10 mM Ca~2+ or Mg~2+, 5 mM Fe~3+, 2 mM Mn~2+ or 1 mM Zn~2+ added to SPP-containing BHI, pH 6.0, at 19℃ resulted in growth comparable to control cultures. Fe~2+ partially restored growth; Ni~2+ Co~2+, Cu~2+ or Al~3+ were ineffective. SPP inhibited growth at 28℃ in BHI, pH 5.0, and Lm grew upon addition of Ca~2+, Mg~2+ or Mn~2+ but not Zn~2+ or Fe~3+. Addition of 0.5/100 SPP to mineral- rich foods, such as pureed beef, green beans or sweet potatoes, did not delay growth.