Microbial Physiology of Alcohol and Hydrogen Production at High Temperatures

***我的研究项目侧重于开发可再生能源，研究高温下大量可用的非食物生物质高效生产酒精和氢气的机制。这是通过表征和修饰代谢途径中涉及的新酶和电子转移活动，以及分离能够产生更多醇或H2的新型超嗜热菌（在高温下茁壮成长的微生物）来实现的。并非所有参与酒精生产代谢途径的关键酶都是已知的，也不是电子转移酶在高温下提高酒精和H2生产效率的调节作用。这种认识的缺乏阻碍了更有效的生物转化系统的发展。我的研究目标是：1)研究生长在90℃及以上条件下产生酒精和H2的超嗜热微生物的生理和应用；2)表征它们的新型耐热酶，如酒精脱氢酶、醛生成酶、电子转移酶和氢化酶，并阐明它们的代谢功能和在生物催化和生产酒精和H2作为生物燃料方面的潜在应用。这将包括表征新分离物，确定所研究的每种酶的生物物理和生化特性，研究它们在代谢途径中的催化作用，以及探索蛋白质热稳定性的机制。生物技术的潜在应用包括绿色化学和大量可用的非食品木质纤维素废料的更强大的生物转化。利用嗜热古菌（Hyperthermus butylicus, Tmax=112℃，一种丁醇产生菌）和细菌（Thermotoga maritima, Tmax=90℃，一种乙醇和H2产生菌）研究酒精和H2代谢的相关机制。将利用生物化学和分子技术研究酶的表达和调控，并对关键酶进行纯化和表征。基因克隆和诱变也将随之进行。在新发现的分离株中，将研究一两个。这项工作的成功完成在加拿大将是独一无二的。这将进一步深入了解超嗜热性醇和H2的代谢以及蛋白质的热稳定性，并阐明高温下醇和H2生成的代谢途径的调控。研究结果可应用于建设更有效的绿色能源生产系统（如乙醇、丁醇、氢气），并将有助于对抗因消耗有限的化石燃料而造成的气候变化和环境恶化的负面影响。HQP将获得进行微生物、分子生物学和生物化学研究的技能和经验，为他们在学术界和食品、生物技术和制药行业的职位做好准备。

***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.