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In anaerobic conditions, this enzyme participates in the fermentation process that occurs in yeast, especially of the genus Saccharomyces, to produce ethanol by fermentation. It is also present in some species of fish (including goldfish and carp ) where it permits the fish to perform ethanol fermentation (along with lactic acid fermentation ...
Despite the bactericidal effects of ethanol, acidifying effects of fermentation, and low oxygen conditions of industrial alcohol production, bacteria that undergo lactic acid fermentation can contaminate such facilities because lactic acid has a low pKa of 3.86 to avoid decoupling the pH membrane gradient that supports regulated transport. [7]
The Crabtree effect, named after the English biochemist Herbert Grace Crabtree, [1] describes the phenomenon whereby the yeast, Saccharomyces cerevisiae, produces ethanol (alcohol) in aerobic conditions at high external glucose concentrations rather than producing biomass via the tricarboxylic acid (TCA) cycle, the usual process occurring aerobically in most yeasts e.g. Kluyveromyces spp. [2 ...
Yeast need a reliable source of nitrogen in forms that they can assimilate in order to successfully complete fermentation. Yeast assimilable nitrogen or YAN is the combination of free amino nitrogen (FAN), ammonia (NH 3) and ammonium (NH 4 +) that is available for a yeast, e.g. the wine yeast Saccharomyces cerevisiae, to use during fermentation.
The measure of the amount of acidity in wine is known as the “titratable acidity” or “total acidity”, which refers to the test that yields the total of all acids present, while strength of acidity is measured according to pH, with most wines having a pH between 2.9 and 3.9. Generally, the lower the pH, the higher the acidity in the wine.
The French chemist Louis Pasteur founded zymology, when in 1856 he connected yeast to fermentation. [9] When studying the fermentation of sugar to alcohol by yeast, Pasteur concluded that the fermentation was catalyzed by a vital force, called "ferments", within the yeast cells. The "ferments" were thought to function only within living organisms.
In the 1990s, few genes were known and analysed by scientists until the first genomic analysis was performed by a team of the Pasteur Institute of Paris. [2] The genome Kluyveromyces lactis was explored by sequencing 588 short tags from two random genomic libraries (random sequenced tags, or RSTs). 296 K. lactis genes were identified of which 292 were new.
Cooler-than-room or refrigeration temperatures decelerate growth and increase the time interval, [18] while slightly warmer temperatures accelerate growth and decrease the time interval. Too warm a temperature slows growth, while even higher temperatures will kill the yeast. Death of the yeast cells occur in the range of 50–60 °C (122–140 ...