The physiology of industrial yeast in continuous culture
type: CreativeWork
description: The physiology of industrial yeasts in continuous culture: F. R. Wardrop The growth and physiology of Saccharomyces cerevisiae GB4918 (baker’s yeast) was studied under glucose-limitation in chemostat culture. Levels of lg/1 (0.1% w /v) glucose allowed cell growth while preventing fermentation in a defined medium (QEMM3). Metabolism of glucose by respiration or fermentation was shown to affect the mean cell volume, with fermentative use of glucose causing an increase in cell size. This was also a major physiological difference between S. cerevisiae GB4918 (a Crabtree positive yeast) and Kliiyveromyces marxianus DBVPG 6165 (a Crabtree negative yeast). The ability of the Crabtree positive yeast to substantially increase its mean cell volume was also reflected in a 5-fold greater consumption of glucose, reduced biomass yield and increased ethanol yield, compared with the Crabtree negative K . marxianus. Growth of both these yeasts was seen in 50g/l glucose in the presence of the respiratory inhibitor, antimycin A. This was evident by the switching to fermentation in K . marxianus, and the complete fermentation of glucose by S. cerevisiae. The growth and physiology of S. cerevisiae GB4918 was also established in glucose-limited chemostat cultures, with special regard to the intracellular macromolecular compounds that are relevant to industrial yeast biomass production. This showed that in respiring cultures of S. cerevisiae, increasing growth rate resulted in decrease in both trehalose and glycogen content, while increasing protein and RNA. This is true until μmax (in this context the growth rate at which respiro-fermentativemetabolism occurs) when accumulation of trehalose and glycogen is apparent. Once μerit (growth rate at which washout of the culture begins) was reached then biomass significantly reduced. In describing the steady-state condition of baker’s yeast it was then possible to describe changes occurring in yeast when subjected to a variety of nutrient pertur…
abstract: The physiology of industrial yeasts in continuous culture: F. R. Wardrop The growth and physiology of Saccharomyces cerevisiae GB4918 (baker’s yeast) was studied under glucose-limitation in chemostat culture. Levels of lg/1 (0.1% w /v) glucose allowed cell growth while preventing fermentation in a defined medium (QEMM3). Metabolism of glucose by respiration or fermentation was shown to affect the mean cell volume, with fermentative use of glucose causing an increase in cell size. This was also a major physiological difference between S. cerevisiae GB4918 (a Crabtree positive yeast) and Kliiyveromyces marxianus DBVPG 6165 (a Crabtree negative yeast). The ability of the Crabtree positive yeast to substantially increase its mean cell volume was also reflected in a 5-fold greater consumption of glucose, reduced biomass yield and increased ethanol yield, compared with the Crabtree negative K . marxianus. Growth of both these yeasts was seen in 50g/l glucose in the presence of the respiratory inhibitor, antimycin A. This was evident by the switching to fermentation in K . marxianus, and the complete fermentation of glucose by S. cerevisiae. The growth and physiology of S. cerevisiae GB4918 was also established in glucose-limited chemostat cultures, with special regard to the intracellular macromolecular compounds that are relevant to industrial yeast biomass production. This showed that in respiring cultures of S. cerevisiae, increasing growth rate resulted in decrease in both trehalose and glycogen content, while increasing protein and RNA. This is true until μmax (in this context the growth rate at which respiro-fermentativemetabolism occurs) when accumulation of trehalose and glycogen is apparent. Once μerit (growth rate at which washout of the culture begins) was reached then biomass significantly reduced. In describing the steady-state condition of baker’s yeast it was then possible to describe changes occurring in yeast when subjected to a variety of nutrient pertur…
author: Wardrop, Forbes
language: eng
date published: 1999-6
date modified: 2026-07-24T00:50:10Z
provider: Abertay University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Abertay Dundee