Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 31, 2000
Publication Date: N/A
Technical Abstract: Development of suitable biocatalysts for the biomass to fuels and chemicals industry remains a significant technical challenge. Our research has focused on modified strains of Rhizopus oryzae for improved lactic acid yield and the use of metabolic engineering to develop Escherichia coli strains with enhanced genetic stability and high ethanol yields. Several genes that are involved in the metabolic scheme of growth and lactate production by R. oryzae have been isolated. We have developed methods to introduce modified genes back into the fungal host and are using this system to decrease production of byproducts and increase accumulation of lactic acid. We also have developed a series of ethanol-producing E. coli strains by transforming Zymomonas mobilis alcohol production genes (pet operon) into strains that cannot grow fermentatively. The pet plasmid is exceptionally stable in our E. coli FBR strains without the addition of antibiotics. Performance of the new recombinants in fermentations of mixe sugars and corn fiber hydrolysates will be discussed.