Wine makers have reasons to cheer as researchers have discovered a system that prevents “stuck fermentation” – a chronic problem that spoils wine.
Working with a prion – an abnormally shaped protein that can reproduce itself – the system enables bacteria in fermenting wine to switch yeast from sugar to other food sources without altering the yeast’s DNA.
In “stuck fermentation”, yeast that should convert grape sugar into alcohol and carbon dioxide prematurely shuts down, leaving the remaining sugar to instead be consumed by bacteria that spoils the wine.
“Our goal now is to find yeast strains that essentially ignore the signal initiated by the bacteria and do not form the prion, but instead power on through the fermentation,” explained Linda Bisson, professor in the department of viticulture and enology at University of California – Davis.
In the study, the researchers found that the interference of the prion causes the yeast to process carbon sources other than glucose and become less effective in metabolising sugar, dramatically slowing down the fermentation until it, in effect, becomes “stuck”.
The study as published in the journal Cell.