Managing mixotrophic algae cultivation for efficient water treatment and biofuel production

管理混合营养藻类培养以实现高效水处理和生物燃料生产

• 批准号: 1438211
• 负责人: Jean VanderGheynst
• 金额: $ 31.75万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1438211&HistoricalAwards=false
• 关键词: Managing; mixotrophic; algae; cultivation; efficient

PI Name: Jean VanderGheynstNumber: 1438211Microalgae have remarkable potential for producing biofuels and bioproducts, and for sequestering carbon dioxide from industrial flue gases. Economical production of algal biofuels will require using nutrients from wastewater and a free source of carbon. The proposed research will involve managing wastewater treatment by mixotrophic microalgae to achieve efficient biofuel production. Mixotrophic algae can grow on either organic carbon sources or atmospheric carbon dioxide. The research has the practical goal of providing an alternative system for biofuel production leading to new industries with high global impact in the areas of energy and agriculture sustainability. Specifically, the use of biofuels produced from microalgal lipids and polysaccharides has been proposed as a potential solution to worldwide challenges related to fossil fuel scarcity and global warming. Furthermore, culturing microalgae in wastewater can improve water quality, and prevent problems associated with "food vs. fuel" competition on limited agriculture lands. This project will also train research and educational leaders who will gain knowledge of fundamental principles and applications of biological engineering and biotechnology. Students will develop an ability to work in multidisciplinary teams to achieve research goals, and gain understanding of the broader issues (global environmental and economic impacts, public/societal views) in the field, preparing them to contribute to science and policy related to energy sustainability. This research will benefit K-12 education through integration of algal research into elementary school science curriculums. It will also benefit undergraduate education through enhanced integration of algal research into an engineering design class at University of California, Davis. Technical DescriptionMicroalgae have been considered as a viable biofuel feedstock due to their productivity and associated higher-value by-products. Recent reports indicate that sustainable economic production of algae for bioenergy will require mixotrophic production on wastewater and waste carbon dioxide. The growth rate of microalgae, uptake of organic carbon, and accumulation of intracellular lipid and polysaccharide products resulting from mixotrophic production will likely be different from heterotrophic and autotrophic production that have been primarily studied to date. Mixotrophic conditions can improve lipid productivity by an order of magnitude. However, these cultures can exhibit low efficiency in converting the carbon source into biofuel precursors. For example, when cultured on glucose, glycerol, and acetate, a model strain of microalgae converted only 10-40% of the substrate energy into lipids and starch. In contrast, yeast cultures can convert glucose to ethanol with 70% efficiency on an energy basis. Elucidating what contributes to lower efficiency in algae is critical for designing algal-based systems for wastewater treatment and biofuel production. The goal of the proposed research is to develop algae cultivation and wastewater management systems that lead to higher substrate utilization efficiencies for biofuel production and organic matter removal from wastewater. Management options include strain selection and algae acclimation, rate and timing of substrate addition and management of wastewater composition. An additional goal is to determine bottlenecks in substrate utilization by microalgae. These goals will be achieved through three objectives. The first objective is to determine if acclimation of microalgae to organic carbon reduces substrate utilization efficiency and develop strategies to overcome this challenge. The second objective is to vary organic carbon and co-factor addition to algae using fed-batch reactors to determine if substrate supply rate impacts conversion efficiency, and the third objective is to use results from objectives 1 and 2 to tailor microalgae production variables for cultivation on food processing wastewaters. This may include application of substrate supply strategies developed in earlier objectives and supplementation of co-factors deficient in wastewaters. Metabolomic profiling techniques will be used to elucidate metabolic responses to different management strategies. This research is expected to inform the decision making process on how to manage microalgae and wastewater for achieving sustainable biofuel production.

PI姓名：Jean VanderGheynst编号：1438211微藻在生产生物燃料和生物产品以及从工业烟道气中隔离二氧化碳方面具有显著的潜力。 藻类生物燃料的经济生产需要使用废水中的营养物质和免费的碳源。拟议的研究将涉及通过兼养微藻管理废水处理，以实现高效的生物燃料生产。 混合营养藻类可以在有机碳源或大气二氧化碳上生长。 该研究的实际目标是为生物燃料生产提供一种替代系统，从而在能源和农业可持续性领域产生具有高度全球影响力的新产业。 具体而言，已经提出使用由微藻脂质和多糖产生的生物燃料作为与化石燃料稀缺和全球变暖相关的全球性挑战的潜在解决方案。 此外，在废水中培养微藻可以改善水质，并防止在有限的农业用地上与“食物与燃料”竞争相关的问题。 该项目还将培训研究和教育领导人，使他们了解生物工程和生物技术的基本原理和应用。学生将培养在多学科团队中工作的能力，以实现研究目标，并了解该领域更广泛的问题（全球环境和经济影响，公众/社会观点），使他们能够为与能源可持续性相关的科学和政策做出贡献。这项研究将有利于K-12教育，通过整合藻类研究到小学科学课程。它还将有利于本科教育，通过加强整合藻类研究到工程设计类在加州大学戴维斯分校。微藻由于其生产力和相关的高价值副产品而被认为是可行的生物燃料原料。最近的报告表明，用于生物能源的藻类的可持续经济生产将需要废水和废二氧化碳的兼养生产。微藻的生长速率、有机碳的吸收以及由兼养生产引起的细胞内脂质和多糖产物的积累将可能不同于迄今为止已经主要研究的异养和自养生产。混合营养条件可以将脂质生产率提高一个数量级。 然而，这些培养物在将碳源转化为生物燃料前体方面可能表现出低效率。例如，当在葡萄糖、甘油和乙酸盐上培养时，微藻的模型菌株仅将10-40%的底物能量转化为脂质和淀粉。相比之下，酵母培养物可以以70%的能量效率将葡萄糖转化为乙醇。 阐明导致藻类效率降低的原因对于设计用于废水处理和生物燃料生产的藻类系统至关重要。 拟议研究的目标是开发藻类培养和废水管理系统，从而提高生物燃料生产和废水中有机物去除的基质利用效率。管理选项包括菌株选择和藻类驯化、底物添加的速率和时间以及废水成分的管理。另一个目标是确定微藻利用底物的瓶颈。这些目标将通过三个目标实现。 第一个目标是确定微藻对有机碳的驯化是否会降低底物利用效率，并制定克服这一挑战的策略。 第二个目标是改变有机碳和辅因子除了藻类使用补料分批反应器，以确定是否基板供应率影响转化效率，和第三个目标是使用目标1和2的结果，以定制微藻生产变量的食品加工废水的培养。这可能包括应用在早期目标中制定的底物供应策略和补充废水中缺乏的辅助因子。代谢组学分析技术将用于阐明不同管理策略的代谢反应。这项研究预计将为如何管理微藻和废水以实现可持续生物燃料生产的决策过程提供信息。