Microbial Physiology of Alcohol and Hydrogen Production at High Temperatures

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My research program focuses on developing renewable energy sources by studying the mechanisms of highly efficient alcohol and H2 production from largely available non-food biomass at high temperatures. This is achieved by characterizing and modifying novel enzymes and electron transfer activities involved in the metabolic pathways and isolating new hyperthermophiles (microbes that thrive at high temperatures) capable of producing greater amounts of alcohols or H2. Not all key enzymes involved in the metabolic pathways of alcohol production are known, nor are the regulatory roles of electron transfer enzymes in enhancing the efficiency of alcohol and H2 production at high temperatures. This lack of understanding hinders the development of more efficient bioconversion systems. My research objectives are to 1) investigate the physiology and applications of alcohol- and H2-producing hyperthermophilic microorganisms growing at 90 C and above, and 2) characterize their novel thermostable enzymes, such as alcohol dehydrogenases, aldehyde-producing enzymes, electron transfer enzymes, and hydrogenases, and elucidate their metabolic functions and potential applications in bio-catalysis and the production of alcohols and H2 as biofuels. This will include characterizing new isolates, determining the biophysical and biochemical properties of each enzyme studied, investigating their catalytic roles in metabolic pathways, and exploring mechanisms of protein thermostability. Potential applications in biotechnology include green chemistry and more robust bioconversion of largely available non-food lignocellulosic waste materials. The mechanisms related to alcohol and H2 metabolism will be investigated using both hyperthermophilic archaea (Hyperthermus butylicus, Tmax=112 C, a butanol producer) and bacteria (Thermotoga maritima, Tmax=90 C, an ethanol and H2 producer). The expression and regulation of enzymes will be studied using biochemical and molecular techniques, with key enzymes purified and characterized. Gene cloning and mutagenesis will be carried out accordingly. Of the new isolates found, one or two will be studied. Successful completion of this work will be unique in Canada. It will provide further insights into hyperthermophilic alcohol and H2 metabolism and protein thermostability, and elucidate the regulation of metabolic pathways for the production of alcohols and H2 at high temperatures. The results can be applied to the construction of more efficient systems for green energy production (e.g., ethanol, butanol, H2) and will serve to combat the negative impacts of climate change and environmental deterioration caused by consuming finite fossil fuels. HQP will gain skills and experience conducting microbiological, molecular biological and biochemical research, preparing them for positions in academia and the food, biotechnological, and pharmaceutical industries.