Bioconversion of plant biomass to ethanol. Annual report and revised research plan, January 1977--January 1978
The objective of this research is to demonstrate on a laboratory scale the technical feasibility of the direct microbial conversion of pretreated wood to ethanol. During the first year of this contract, we investigated the feasibility of biologically delignifying wood with C. pruinosum and directly fermenting the pretreated wood to ethanol with a mixed culture. Bench-top fermentations of a thermophilic bacillus growing on glucose and of a mixed culture of thermophilic sporocytophaga (US) and a thermophilic bacillus growing on microcrystalline and amorphous cellulose were evaluated for growth and ethanol production. In the mixed culture fermentation of amorphous and microcrystalline cellulose, the specific rate of substrate depletion was calculated to be 0.087 hr/sup -1/ and 0.0346 hr/sup -1/, respectively. However, defining the growth requirements of C. pruinosum and sporocytophaga (US) proved more difficult than originally anticipated. In order to achieve the program objectives within the contract period, a revised research plan was developed based upon chemical pretreatment and the direct fermentation of pretreated hardwood to ethanol. In place of the biological delignification pretreatment step, we have substituted a chemically supplemented steam pretreatment step to partially delignify wood and to enhance its accessibility to microbial utilization. Clostridium thermocellum, which ferments cellulose directly to ethanol and acetic acid, has replaced the mixed culture fermentation stage for ethanol production. Research on the production of ethanol from xylose by the thermophilic bacillus ZB-B2 is retained as one means of utilizing the hemicellulose fraction of hardwood. Work on the genetic improvement of the ethanol yields of both cultures by suppressing acetic acid production is also retained. The rationale, experimental approach, and economic considerations of this revised research plan are also presented.
- Research Organization:
- General Electric Co., Schenectady, NY (USA)
- DOE Contract Number:
- EG-77-C-02-4147
- OSTI ID:
- 6643423
- Report Number(s):
- COO-4147-4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Bioconversion of plant biomass to ethanol. Final report, 15 December 1976-31 December 1978
Bioconversion of plant biomass to ethanol. First bimonthly and quarterly report
Related Subjects
ETHANOL
BIOSYNTHESIS
WOOD
DELIGNIFICATION
ENZYMATIC HYDROLYSIS
FERMENTATION
XYLOSE
BIODEGRADATION
CELLULOSE
CLOSTRIDIUM
FUNGI
HEMICELLULOSE
PROCESSING
STEAM
THERMOPHILIC CONDITIONS
ALCOHOLS
ALDEHYDES
BACTERIA
BIOCONVERSION
CARBOHYDRATES
CHEMICAL REACTIONS
DECOMPOSITION
HYDROLYSIS
HYDROXY COMPOUNDS
LYSIS
MICROORGANISMS
MONOSACCHARIDES
ORGANIC COMPOUNDS
PENTOSES
PLANTS
POLYSACCHARIDES
SACCHARIDES
SOLVOLYSIS
SYNTHESIS
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