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名称：Jean Vandergheynstnumber：1438211Microalgae具有产生生物燃料和生物产品的显着潜力，以及从工业烟道气体中隔离二氧化碳。 藻类生物燃料的经济生产将需要使用废水和自由碳来源的营养。拟议的研究将涉及通过混合营养微藻处理的废水处理，以实现有效的生物燃料生产。 综合藻类可以在有机碳源或大气二氧化碳上生长。 该研究的实用目标是为生产生产提供替代系统，从而导致新行业对能源和农业可持续性领域具有很大的影响。 具体而言，已提出使用微脂质和多糖生产的生物燃料，作为解决与化石燃料稀缺和全球变暖有关的全球挑战的潜在解决方案。 此外，在废水中培养微藻可以提高水质，并防止与有限农业土地上的“食物与燃料”竞争有关的问题。 该项目还将培训研究和教育领导者，他们将了解生物工程和生物技术的基本原理和应用。学生将建立在多学科团队中工作的能力，以实现研究目标，并了解该领域的更广泛的问题（全球环境和经济影响，公共/社会观点），为他们做好了为与能源可持续性相关的科学和政策做出贡献的准备。这项研究将通过将藻类研究整合到小学科学课程中，使K-12教育受益。它还将通过将藻类研究加入加利福尼亚大学戴维斯分校的工程设计课程，使本科教育受益。由于其生产力和相关的高价值副产品，技术描述被认为是可行的生物燃料原料。最近的报道表明，生物能源的藻类的可持续经济生产将需要在废水和废水二氧化碳上产生造成营养性。微藻的生长速率，有机碳的吸收以及造成杂食产量引起的细胞内脂质和多糖产物的积累可能与迄今为止主要研究的杂营和自养生产不同。多营养条件可以通过数量级提高脂质生产率。 但是，这些培养物可以在将碳源转化为生物燃料前体时表现出较低的效率。例如，当在葡萄糖，甘油和醋酸酯上培养时，微藻的模型应变仅转化为10-40％的底物能将其转化为脂质和淀粉。相比之下，酵母培养物可以在能量基础上以70％的效率将葡萄糖转化为乙醇。 阐明什么促进藻类效率降低的因素对于设计用于废水处理和生物燃料生产的基于藻类的系统至关重要。 拟议的研究的目的是开发藻类培养和废水管理系统，从而提高较高的底物利用率，以从废水中生产生物燃料生产和有机物清除。管理选项包括菌株选择和藻类适应，底物添加的速率和时机以及废水组成的管理。另一个目标是确定微藻利用底物利用的瓶颈。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适应是否会降低底物利用效率，并制定克服这一挑战的策略。 第二个目标是使用饲料批量反应器改变有机碳和联合因子为藻类增加，以确定底物供应率是否影响转化效率，第三个目标是使用目标1和2的结果来量化微藻生产变量，以在食品加工废水中培养用于培养。这可能包括应用在早期目标中开发的基板供应策略以及补充废水中缺乏的副因素。代谢分析技术将用于阐明对不同管理策略的代谢反应。预计这项研究将为如何管理微藻和废水以实现可持续的生物燃料生产而告知决策过程。