Biotechnology for Production of Fuels, Chemicals, and Materials from Biomass

Biological systems can convert renewable resources, including lignocellulosic biomass, starch crops, and carbon dioxide, into fuels, chemicals, and materials. Ethanol and other products are now derived from starch crops, such as corn. Enzyme-based technology is under development for conversion of lignocellulosic biomass (e.g., wood, grasses, and agricultural and municipal wastes) into fuel ethanol. The simultaneous saccharification and fermentation (SSF) process is employed to convert the cellulose fraction into ethanol at improved rates, higher yields, and higher ethanol concentrations than using sequential processing through careful selection of improved cellulase enzymes and fermentative microorganisms. Medium-BTU gas can be derived from lignocellulosic biomass by anaerobic digestion and cleaned up to a pipeline-quality gas. A high-solids fermenter achieves higher gas generation rates than conventional devices and promises to help make such gas economical. An extensive collection of more than 500 productive strains of microalgae has been established to produce lipid oils for diesel fuel and other compounds from carbon dioxide. Acetyl CoA carboxylase (ACC) has been shown to be a key enzyme in lipid oil synthesis, and genetic engineering approaches are being applied to enhance the rates and yields of product formation. In addition to fuels, a biorefinery could produce a wide range of chemicals and materials through microbial conversion of renewable resources, and technology is being developed for production of chemicals and materials from biomass. Index Entries: Ethanol; methane; biodiesel; chemicals; biomass. *Author to whom all correspondence and reprint requests should be addressed. Applied Biochernistry and Biotechnology 41 Vol. 39/40, 1993 42 Wyman and Goodman