COLLABORATIVE RESEARCH: Exploiting microbial hyperthermophilicity to produce an industrial chemical

1264052/1264053 Kelly/Adams 微生物代谢工程的发展很大程度上基于有限数量的重组宿主（例如大肠杆菌、酿酒酵母），因为对这些微生物的生理学有丰富的了解并且相关分子遗传工具的可用性。然而，随着代谢工程针对越来越多的创新生物加工目标，迫切需要扩大潜在微生物宿主的范围。由于嗜极微生物已经被赋予了能够适应工业过程的恶劣条件特征的特性，因此为这组微生物开发代谢工程能力是有意义的。直到最近，这个方向还是难以置信的，但新开发的分子遗传工具和基因组学研究为极端微生物的代谢工程开辟了前景。因此，这个拟议的项目将证明对超嗜热古菌——激烈热球菌进行代谢改造的功效，该细菌在 100°C 下生长最佳。为了证明这种微生物确实可以进行代谢工程，这项工作将建立在最近在温度依赖性生化加工方面取得的成功的基础上，现在将从纤维二糖和麦芽糖生产一种特种化学品琥珀酸。从最适温度值接近 70°C 的不太耐热的生物体中鉴定出的编码转运蛋白和代谢酶的基因将被导入重组的强烈狂犬病菌株中。将利用战略性地利用超嗜热性的基因调控和产物形成的新方法来优化在 70°C 附近生物产物形成的产量和效率。提供一个通过代谢工程改造超嗜热宿主以生产非生理产品的范例，将为基于热的生物加工机会铺平道路。对学生进行分子生物化学、功能基因组学和生物分子工程研究极端微生物生物学和生物技术的跨学科培训将产生更广泛的影响。每个秋季学期将招募两名本科生研究人员，并在随后获得 PI 实验室暑期研究经验的支持（一名佐治亚大学生物化学家和北卡罗来纳州立大学一名化学工程师）。这些学生将在暑假期间在另一个合作实验室度过两周的时间，以促进跨学科培训。北卡罗来纳州立大学和佐治亚大学参与本项目及相关项目的所有学生都将参加夏季期间在 NSCU 和佐治亚大学轮流举办的一年一度的“嗜热菌小组会议”。这将促进跨学科培训和合作，并提供交流研究思想和方法的机制。

1264052/1264053 Kelly/AdamsThe development of microbial metabolic engineering has largely been based on a limited number of recombinant hosts (e.g., Escherichia coli, Saccharomyces cerevisiae) because of the substantial knowledge of the physiology of these microorganisms and availabilityof associated molecular genetic tools. However, as metabolic engineering is directed at more and more innovative bioprocessing objectives, there is a pressing need to expand the range of potential microbial hosts. Because extremophiles are already endowed with properties that are amenable to the harsh conditions characteristic of industrial processes, it makes sense to develop metabolic engineering capabilities for this group of microorganisms. This direction would have been implausible until very recently, but newly developed molecular genetic tools and genomics studies have opened up the prospects for metabolic engineering of extremophiles. As such, this proposed project will demonstrate the efficacy of metabolically engineering the hyperthermophilic archaeon, Pyrococcus furiosus, which grows optimally at 100°C. To demonstrate that this microorganism can, indeed, be metabolically engineered, the work will build upon recent success in temperature-dependent biochemical processing and will now produce a specialty chemical, succinate, from cellobiose and maltose. Genes encoding transporters and metabolic enzymes identified from less thermophilic organisms with optimum temperature values near 70°C will be imported into a recombinant P. furiosus strain. Novel approaches for gene regulation and product formation that strategically exploit hyperthermophilicity will be utilized to optimize yields and efficiencies for bioproduct formation near 70°C. Providing a paradigm for metabolically engineering a hyperthermophilic host to produce a non-physiological product will pave the way for thermally-based, bioprocessing opportunities.Broader impacts will result from the interdisciplinary training of students in molecular biochemistry, functional genomics and biomolecular engineering for studying extremophile biology and biotechnology. Two undergraduate researchers will be recruited during each fall semester and be supported subsequently for a summer research experience in the PI's laboratories (one biochemist at UGA and one chemical engineer at NCSU). These students will spend two weeks during the summer at the other collaborating lab to foster interdisciplinary training. All students on this and related projects at NCSU and UGA will participate in an annual extended 'Hyperthermophile Group Meeting' during the summer to be hosted at NSCU and UGA on an alternating basis. This will foster interdisciplinary training and collegiality, as well as provide a mechanism for exchange of research ideas and methodologies.