skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Bioconversion of plant biomass to ethanol. Annual report and revised research plan, January 1977--January 1978

Abstract

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 directlymore » 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.« less

Authors:
; ;
Publication Date:
Research Org.:
General Electric Co., Schenectady, NY (USA)
OSTI Identifier:
6643423
Report Number(s):
COO-4147-4
DOE Contract Number:  
EG-77-C-02-4147
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; 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; 090222* - Alcohol Fuels- Preparation from Wastes or Biomass- (1976-1989); 140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)

Citation Formats

Brooks, R. E., Bellamy, W. D., and Su, T. M. Bioconversion of plant biomass to ethanol. Annual report and revised research plan, January 1977--January 1978. United States: N. p., 1978. Web. doi:10.2172/6643423.
Brooks, R. E., Bellamy, W. D., & Su, T. M. Bioconversion of plant biomass to ethanol. Annual report and revised research plan, January 1977--January 1978. United States. https://doi.org/10.2172/6643423
Brooks, R. E., Bellamy, W. D., and Su, T. M. 1978. "Bioconversion of plant biomass to ethanol. Annual report and revised research plan, January 1977--January 1978". United States. https://doi.org/10.2172/6643423. https://www.osti.gov/servlets/purl/6643423.
@article{osti_6643423,
title = {Bioconversion of plant biomass to ethanol. Annual report and revised research plan, January 1977--January 1978},
author = {Brooks, R. E. and Bellamy, W. D. and Su, T. M.},
abstractNote = {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.},
doi = {10.2172/6643423},
url = {https://www.osti.gov/biblio/6643423}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Mar 23 00:00:00 EST 1978},
month = {Thu Mar 23 00:00:00 EST 1978}
}