TITLE:
Acid and Heat Mild Stresses Improve the Overall Heat Tolerance of Leuconostoc mesenteroides
AUTHORS:
Ingrid Osorio, Douglas Olson, Kayanush Aryana
KEYWORDS:
Probiotic, Thermal, Stressor, Food
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.16 No.12,
December
19,
2025
ABSTRACT: The importance of Leuconostoc mesenteroides is recognized for its contribution to taste in cultured dairy products and has been cited for its potential role as a probiotic. Objective was to evaluate the effect of prior exposure to various mild stress conditions on the survival of Leuconostoc mesenteroides in challenging heat conditions. Leuconostoc mesenteroides spp. cremoris Vivolac Cremosa CIT/FPC Series cells were subjected to four mild stresses (acid, heat, ethanol and oxidative). Each mild stress had three levels of intensity: low, medium and high. Then culture was subjected to challenging heat conditions. The de Man Rogosa Sharpe Agar was used for plating. The experiments were repeated three times with duplicate readings. Data were analyzed as a Randomized Block Design using the Glimmix procedure and Tukey mean separation. Heat tolerance of Leuconostoc mesenteroides at 60˚C was significantly enhanced by subjecting the bacteria to heat mild treatments of 30˚C, 35˚C and 45˚C (P Leuconostoc mesenteroides ssp. cremoris was improved by prior exposure to temperatures between 30˚C - 45˚C which led to improved viability (63% - 55%) upon heat shock at 60˚C for 3 minutes. In addition, we observed cross-protection in Leuconostoc mesenteroides to heat treatment at 60˚C induced by acid pH 5.0, 4.5 and 4.0. This enhanced heat tolerance has potential applications for Leuconostoc mesenteroides spp. cremoris in food products in which such a challenging condition is encountered.