Selection of ethanol-tolerant yeast hybrids in pH-regulated continuous culture
Hybrids between naturally occurring wine yeast strains and laboratory strains were formed as a method of increasing genetic variability to improve the ethanol tolerance of yeast strains. The hybrids were subjected to competition experiments under continuous culture controlled by pH with increasing ethanol concentrations over a wide range to select the fastest-growing strain at any concentration of ethanol. The continuous culture system was obtained by controlling the dilution rate of a chemostat connected to a pH-meter. The nutrient pump of the chemostat was switched on and off in response to the pH of the culture, which was thereby kept near a critical value (pH/sub c/). Under these conditions, when the medium was supplemented with ethanol, the ethanol concentration of the culture increased with each pulse of dilution. A hybrid strain was selected by this procedure that was more tolerant than any of the highly ethanol-tolerant wine yeast strains at any concentration of ethanol and was able to grow at up to 16% (vol/vol) ethanol. This improvement in ethanol tolerance led to an increase in both the ethanol production rate and the total amount of ethanol produced.
- Research Organization:
- Universidad de Sevilla (Spain)
- OSTI ID:
- 6993667
- Journal Information:
- Appl. Environ. Microbiol.; (United States), Vol. 54:4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
09 BIOMASS FUELS
ETHANOL
TOLERANCE
YEASTS
GENETIC ENGINEERING
CONTINUOUS CULTURE
GENETIC VARIABILITY
HYBRIDIZATION
PH VALUE
ALCOHOLS
BIOLOGICAL VARIABILITY
FUNGI
HYDROXY COMPOUNDS
MICROORGANISMS
ORGANIC COMPOUNDS
PLANTS
560300* - Chemicals Metabolism & Toxicology
090222 - Alcohol Fuels- Preparation from Wastes or Biomass- (1976-1989)