Construction of lactose-assimilating and high-ethanol-producing yeasts by protoplast fusion
The availability of a yeast strain which is capable of fermenting lactose and at the same time is tolerant to high concentrations of ethanol would be useful for the production of ethanol from lactose. Kluyveromyces fragilis is capable of fermenting lactose, but it is not as tolerant as Saccharomyces cerevisiae to high concentrations of ethanol. In this study, the authors have used the protoplast fusion technique to construct hybrids between auxotrophic strains of S. cerevisiae having high ethanol tolerance and an auxotrophic strain of lactose-fermenting K. fragilis isolated by ethyl methanesulfonate mutagenesis. The fusants obtained were prototrophic and capable of assimilating lactose and producing ethanol in excess of 13% (vol/vol). The complementation frequency of fusion was about 0.7%. Formation of fusants was confirmed by the increased amount of chromosomal DNA per cell. Fusants contained 8 x 10/sup -9/ to 16 x 10/sup -8/ ..mu..g of DNA per cell as compared with about 4 x 10/sup -8/ ..mu..g of DNA per cell for the parental strains, suggesting that multiple fusions had taken place.
- Research Organization:
- Univ. of California, Davis
- OSTI ID:
- 6231219
- Journal Information:
- Appl. Environ. Microbiol.; (United States), Journal Name: Appl. Environ. Microbiol.; (United States) Vol. 51:2; ISSN AEMID
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
090222* -- Alcohol Fuels-- Preparation from Wastes or Biomass-- (1976-1989)
ALCOHOLS
BIOCONVERSION
BIOLOGY
CARBOHYDRATES
DISACCHARIDES
DNA
ETHANOL
FERMENTATION
FUNGI
GENETICS
HYBRIDIZATION
HYDROXY COMPOUNDS
LACTOSE
MICROORGANISMS
NUCLEIC ACIDS
OLIGOSACCHARIDES
ORGANIC COMPOUNDS
PLANT CELLS
PLANTS
SACCHARIDES
SACCHAROMYCES
SACCHAROMYCES CEREVISIAE
YEASTS
YIELDS