Influence of the sporulation temperature on the impact of the nutrients inosine and l-alanine on Bacillus cereus spore germination

Food Microbiol. 2008 Feb;25(1):202-6. doi: 10.1016/j.fm.2007.08.002. Epub 2007 Sep 3.

Abstract

The effect of sporulation temperature on Bacillus cereus spore germination triggered by the nutrient germinants inosine and l-alanine was investigated. The germination (expressed as % A(600nm) fall) of heat-activated spores of B. cereus strain ATCC14579 produced at 20 and 37 degrees C, and of psychrotrophic strains LM9 and D15 produced at 15 and 37 degrees C was followed in a germination buffer containing inosine at concentrations between 0.01 and 10mmoll(-1), or l-alanine between 1 and 100mmoll(-1). Spores wet-heat resistance at 90 degrees C was also determined. Spores of the three strains produced at the lowest temperatures generally showed a higher germination capacity in response to both inosine and in l-alanine than those produced at 37 degrees C, and were also more susceptible to heat. Low sporulation temperature is confirmed as a detrimental factor to B. cereus spore wet-heat resistance, and conversely gave spores with a sensitivity to the nutrient germinants inosine and l-alanine higher than that of spores formed close to the maximal sporulation temperature.

MeSH terms

  • Alanine / pharmacology*
  • Bacillus cereus / physiology*
  • Colony Count, Microbial
  • Consumer Product Safety
  • Dose-Response Relationship, Drug
  • Food Microbiology
  • Inosine / pharmacology*
  • Spores, Bacterial / drug effects*
  • Spores, Bacterial / growth & development
  • Temperature
  • Time Factors

Substances

  • Inosine
  • Alanine