Bacterial cell adaptation to environmental stress during fermentation improves cryo-and drying resistance: A focus on membrane properties - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2020

Bacterial cell adaptation to environmental stress during fermentation improves cryo-and drying resistance: A focus on membrane properties

Résumé

The resistance of lactic acid bacteria to freezing and freeze-drying is influenced by the cell membrane's biophysical properties, which in turn is governed by the environmental conditions applied during bacterial growth. Our work aimed at identifying the key environmental factors and membrane properties for improving bacterial resistance. L. bulgaricus CFL1 was cultivated at two temperatures and three pH conditions. Cells were harvested at different growth phases (from the middle exponential phase to the late stationary phase). Cultivability and acidification activity losses of L. bulgaricus CFL1 were quantified after freezing, freeze-drying. Bacterial membranes were characterized by determining the fatty acid composition, the lipid phase transition, and the membrane fluidity. The intracellular glass transition temperature of the bacterial pellet was also determined. The bacterial growth conditions modulated the bacterial resistance, the biophysical membrane properties, and the intracellular cell content. Improved bacterial resistances to freezing and freeze-drying were obtained with different fermentation conditions. Notably, cells cultivated at low pH improved cryo-resistance. A significant effect on the cells' biochemical and biophysical properties was observed when cells were cultivated at high growth temperature. Results from this work will allow increasing our knowledge about the physiological mechanisms that explain the resistance of L. bulgaricus CFL1 to freezing and freeze-drying. Furthermore, this study illustrates the relevance of complementary methods for characterizing bacterial cells' biophysical properties in response to environmental stress.
Fichier non déposé

Dates et versions

hal-04398166 , version 1 (16-01-2024)

Identifiants

  • HAL Id : hal-04398166 , version 1

Citer

Maria de L Tovilla-Coutino, Stéphanie Passot, Jérôme Delettre, Sarrah Ghorbal, Marie-Hélène Ropers, et al.. Bacterial cell adaptation to environmental stress during fermentation improves cryo-and drying resistance: A focus on membrane properties. 5th Microbial Stress Conference of the European Federation of Biotechnology, Nov 2020, Virtual, France. ⟨hal-04398166⟩
18 Consultations
0 Téléchargements

Partager

Gmail Mastodon Facebook X LinkedIn More