Genetic engineering of bacteria for lignocellulose conversion to ethanol

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:141373

Ingram, L O ^[1]

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1. Univ. of Florida, Gainsville, FL (United States)

The dominant cost for U.S. ethanol fuel production today is the substrate, corn starch. Expansion of this fermentation process to include additional substrates such as lignocellulose offers great potential to reduce this cost and increase the use of ethanol as a fuel additive. Lignocellulose is a more complex substrate than starch and is a mixture of carbohydrate polymers (hemicellulose and cellulose) and lignin. This substrate needs both depolymerization to release sugars and fermentation of mixed hexose and pentose sugars. During the past few years the authors` laboratory has developed a series of genetically engineered bacteria which efficiently ferment all of the sugars present in lignocellulose. This was done by inserting a portable, artificial operon containing the Z. mobilis genes for alcohol dehydrogenase and pyruvate decarboxylase into other bacteria which have the native ability to metabolize diverse sugars. Organisms are now being developed which also produce some of the enzymes needed for the depolymerization of cellulose, cellotriose, xylobiose, xylotriose, maltose, maltotriose, etc. improving the process by eliminating the requirement for monomeric sugars for fermentation. Efficiencies of conversion exceed 90% of theoretical yields. These organisms are being commercialized for fuel ethanol production.

• OSTI ID: 141373
• Report Number(s): CONF-930304--
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
55 BIOLOGY AND MEDICINE
BASIC STUDIES
BACTERIA
BIOCONVERSION
BIOSYNTHESIS
ETHANOL
FERMENTATION
GENETIC ENGINEERING
HEMICELLULOSE
LIGNIN