UNS: Targeted saturated fatty acids synthesis by microbial biohydrogenation and its superior extraction from microalgae biomass through selective fermentation

PI名称：Bruce E.Rittmann Proposal编号：1509933微藻是一种单细胞光合作用生物体，依靠大气中的二氧化碳、阳光和溶解的矿物质养分生长。在适当的条件下，微藻还会产生以脂肪形式储存的脂肪酸，这些脂肪酸可以很容易地转化为生物燃料，如生物柴油。这项拟议的研究将探索一种名为选择性发酵的新工艺，以解决藻类生物燃料生产工艺继续商业化发展面临的两大障碍：安全高效地提取油脂，以及有益地利用非油脂生物质。选择性发酵包括将微藻生物量中的碳水化合物和蛋白质部分转化为短链脂肪酸，同时保持脂肪部分的完整性，更容易用无毒溶剂提取。这项研究有可能提高藻类生物质的生物燃料产量并减少废物，从而提高效率并促进藻类生物燃料生产过程的可持续性。利用微藻生产液体运输燃料面临着许多挑战，包括安全高效地提取油脂，以及有效利用生物质中的非油脂成分。该项目将研究选择性发酵的潜力，以同时应对这两个挑战。在所提出的选择性发酵过程中，微藻生物量中的碳水化合物和蛋白质部分被发酵成短链脂肪酸，而现有的脂肪部分以一种更容易从未发酵的生物量中提取的形式保存。为了提高碳水化合物和蛋白质发酵的速度和程度，将在微生物电解槽(MEC)的阳极室进行选择性发酵过程，MEC在阴极产生氢气，消耗发酵产物，促进不饱和脂肪酸的生物加氢生成更高燃料质量的饱和脂肪酸。将开发数学模型，将关键的生化、微生态和电化学机制联系起来，以提高对整个系统中这些过程相互作用的基本了解，并使未来能够对该过程进行技术经济和生命周期分析。该项目的教育方面将促进绿色劳动力的发展，方法是让当地社区大学中代表性不足群体的学生参加全年研究体验，并支持高中教师和学生进行结对的暑期实习。

PI Name: Bruce E. RittmannProposal Number: 1509933Microalgae are single-celled photosynthetic organisms that grow on atmospheric carbon dioxide, sunlight, and dissolved mineral nutrients. Under the proper conditions, microalgae also produce fatty acids stored as lipids, which can be readily converted to biofuel such as biodiesel. This proposed research will explore a new process called selective fermentation to address two major roadblocks facing the continued commercial development algal biofuel production processes: safe and efficient extraction of the lipids, and beneficial use of the non-lipid biomass. Selective fermentation involves the conversion of carbohydrate and protein fractions of microalgae biomass to short-chain fatty acids while leaving the lipid fraction intact and more easily available for extraction by non-toxic solvents. This research has the potential to improve biofuel yield from algal biomass and reduce waste, thereby increasing efficiency and promoting sustainability of algal biofuel production processes. The production of liquid transportation fuels from microalgae faces many challenges, including the safe and efficient extraction of lipids, and in the beneficial use of the non-lipid components in the biomass. This project will study the potential of selective fermentation to simultaneously address these two challenges. In the proposed selective fermentation process, the carbohydrate and protein fractions of the microalgal biomass are fermented to short-chain fatty acids, while the existing lipid fraction is conserved in a form that is more readily extracted from the non-fermented biomass. To increase the rate and extent of carbohydrate and protein fermentation, the selective fermentation process will be carried out in the anode chamber of a microbial electrolysis cell (MEC), which produces hydrogen gas at the cathode, consumes the fermentation products, and promotes bio-hydrogenation of unsaturated fatty acids to saturated fatty acids with higher fuel quality. Mathematical models will be developed to link the key biochemical, microecological, and electrochemical mechanisms to improve fundamental understanding of the interactions of these processes in the overall system, and will enable future techno-economic and life-cycle analysis of the process. The education aspects of this project will advance the development of a green workforce by involving students from under-represented groups at a local community college in year-round research experiences, and by supporting a high school teacher and student in paired summer internships.