Behaviour of Saccharomyces cerevisiae wine strains during adaptation to unfavourable conditions of fermentation on synthetic medium: cell lipid composition, membrane integrity, viability and fermentative activity.
During must fermentation wine strains are exposed to a variety of biotic and abiotic stresses which, when prevailing over the cellular defence systems, can affect cell viability with negative consequences on the progression of the fermentative process. To investigate the ability of wine strains to survive and adapt to unfavourable conditions of fermentation, the lipid composition, membrane integrity, cell viability and fermentative activity of three strains of Saccharomyces cerevisiae were analysed during hypoxic growth in a sugar-rich medium lacking lipid nutrients. These are stressful conditions, not unusual during must fermentation, which, by affecting lipid biosynthesis may exert a negative effect on yeast viability. The results obtained showed that the three strains were able to modulate cell lipid composition during fermentation. However, only two of them, which showed highest viability and membrane integrity at the end of the fermentation process, reached a fatty acid composition which seemed to be optimal for a successful adaptation. In particular, C16/TFA and UFA/TFA ratios, more than total lipid and ergosterol contents, seem to be involved in yeast adaptation.
Dipartimento di Scienze degli Alimenti, Università Politecnica delle Marche, Via Brecce Bianche, 60131, Ancona, Italy.
Ilaria
I
Mannazzu
Daniele
D
Angelozzi
Simona
S
Belviso
Marilena
M
Budroni
Giovanni Antonio
GA
Farris
Paola
P
Goffrini
Tiziana
T
Lodi
Mario
M
Marzona
Laura
L
Bardi
D000222:Adaptation, Physiological; D004875:Ergosterol / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis*; D005285:Fermentation; D005434:Flow Cytometry; D005516:Food Microbiology; D008563:Membrane Lipids / Q000032:analysis*; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism / Q000502:physiology; D013997:Time Factors; D014920:Wine / Q000382:microbiology*
D005227:Fatty Acids; D008563:Membrane Lipids; D004875:Ergosterol