Research will be carried out focusing on renewable resources and waste treatment. The capabilities of living systems will be explored in this context, using an integrated approach employing engineering, biological, and chemical principles. A particular focus is fundamental understanding which could make a contribution toward the realization of applied goals. Specific areas of interest include ethanol production from lignocellulose, and anaerobic waste treatment and remediation. Current and anticipated research related to ethanol production addresses metabolic control of product formation, cellulase kinetics, and bioreactor design. Thermophilic bacteria and enzymes are of particular interest. Investigation of metabolic control will involve coupling understanding of microbial physiology and energetics with engineering approaches to manipulating the fermentor environment in order to increase ethanol yields. Bioreactor design for continuous fermentation of lignocellulosics at high concentrations will be pursued both experimentally and theoretically. This will encompass consideration of plug-flow cellulose distribution, differential residence time of both cells and substrate due to substrate-broth density differences and cell-substrate adhesion phenomena, and modeling and understanding in vivo cellulose hydrolysis and fermentation. Approaches to anaerobic waste treatment and remediation will include selective inhibition of sulfate-reducing bacteria (SRB) via biochemically-based strategies. In addition, the physiological basis for the relatively incomplete treatment often obtained by anaerobic systems, and possible solutions to this problem, will be addressed. Finally, the use of anaerobic systems for the detoxification of hazardous wastes will be investigated, including both engineering and biological considerations.
