Weak organic acid treatment causes a trehalose accumulation in low-pH cultures of Saccharomyces cerevisiae, not displayed by the more preservative-resistant Zygosaccharomyces bailii.

Abstract

Weak organic acid food preservatives exert pronounced culture pH-dependent effects on both the heat-shock response and the thermotolerance of Saccharomyces cerevisiae. In low-pH cultures, they inhibit this stress response and cause strong induction of respiratory-deficient petites amongst the survivors of lethal heat treatment. In higher pH cultures, 25 degrees C sorbic acid treatment causes a strong induction of thermotolerance without inducing the heat-shock response. In this study we show that trehalose, a major stress protectant, accumulates rapidly in S. cerevisiae exposed to sorbate at low pH. In pH 3.5 cultures, a 25 degrees C sorbate treatment is as effective as a 39 degrees C heat shock in inducing trehalose. This weak-acid-induced trehalose accumulation is enhanced in the pfk1 S. cerevisiae mutant, indicating that it arises through inhibition of glycolysis at the phosphofructokinase step. The more preservative-resistant food spoilage yeast Zygosaccharomyces bailii differs from S. cerevisiae in that: (1) its basal thermotolerance is not strongly affected by culture pH; (2) it does not display trehalose accumulation in response to 25 degrees C sorbate treatment at low pH; and (3) there is no induction of respiratory-deficient petites during lethal heating with sorbate. This probably reflects Z. bailii being both petite-negative and better equipped for maintenance of homeostasis during weak-acid, pH or high-temperature stress.

• Authors: L Cheng, J Moghraby, P W Piper
• Journal: FEMS microbiology letters (FEMS Microbiol Lett) Vol. 170 Issue 1 Pg. 89-95 (Jan 01 1999) ISSN: 0378-1097 [Print] England
• PMID: 9919656 (Publication Type: Journal Article)

Chemical References

• Food Preservatives
• Trehalose
• Phosphofructokinase-1
• Sorbic Acid

Topics

• Food Preservatives (pharmacology)
• Glycolysis
• Heat-Shock Response
• Hydrogen-Ion Concentration
• Phosphofructokinase-1 (metabolism)
• Saccharomyces cerevisiae (drug effects, growth & development, metabolism)
• Sorbic Acid (pharmacology)
• Trehalose (metabolism)
• Zygosaccharomyces (drug effects, growth & development, metabolism)