Sustainable Bioconversion of Liquid Biofuels: Linking Organic Waste Processing and Microalgae Cultivation

1236691 Betenbaugh/Bouweralgae是一种潜在的有价值的可再生液体燃料来源，包括柴油和喷气燃料。这些液体燃料是从藻类生物量积累过程中产生的脂类中提取出来的，是飞机和机动车辆使用的石油液体燃料的替代品。藻类生物量可通过光合作用(光自养)、有机碳源(异养)或有机碳和阳光的组合(混合营养)产生。不幸的是，仅通过光合作用产生的藻类生物燃料过程通常只产生少量的藻类生物量，并减少油脂的产量。或者，当补充有机碳和其他营养物质时，藻类可以产生更高水平的生物量和高脂肪产量。然而，添加葡萄糖等传统有机碳源增加了生产成本，阻碍了商业可行性。一个同样紧迫的可持续性问题是农业、工业和城市有机废物的积累和处置所产生的环境影响和成本。这项研究计划将通过将有机废物处理过程与使用微藻生物处理产生液体燃料相结合，同时解决可持续发展和能源问题。具体地说，该项目旨在改变废物处理，以产生更多可供微藻消耗的有机碳源，并操纵微藻，使这些宿主能够消耗从人为有机废物中获得的更多种类的碳源。该项目的具体目标如下：1)优化环境废物处理(发酵)，以产生可供微藻消耗的高产量有机营养物质；2)从基因上操纵微藻，以使这些细胞消耗更多的有机废物副产品。在布维尔实验室，将操纵有机废物处理条件，包括化学和生物预处理步骤以及碳和氮含量，以增加有机质向目标有机酸的转化。不幸的是，虽然微藻可以消耗一些有机酸，但许多藻类无法处理废物处理过程中产生的其他有机酸副产品。因此，Betenbaugh实验室项目的第二个目标是重新编程微藻细胞新陈代谢，使它们能够消耗该物种通常不会消耗的额外有机废物副产品。世界面临的三个最大的可持续性挑战是环境污染、对不可再生化石燃料的过度依赖和全球变暖。长期解决方案应考虑同时处理多个可持续性问题的整体办法。该计划通过将有机液体废物处理与微藻生长和油脂生产相结合来解决这些挑战，以产生可再生的液体生物燃料。微藻利用有机废物将减少威胁我们河流、湖泊和海洋的农业、工业和生活废物径流，并将在最需要就业机会的地区创造就业机会。这项技术可以与现有的农业和生活垃圾处理设施相结合，用于可再生能源发电、经济发展和社区自给自足。另一个同样重要的目标是发展注重可持续性的新的教育模式。通过与巴尔的摩少数公立STEM高中的合作，学生将在网络和实验室环境(包括当地的植物园)中使用动手方法从微藻中产生生物燃料。此外，约翰霍普金斯大学正在开发以生物能源、生物可持续发展和环境恢复为重点的课堂和实验室课程。因此，拟议的项目将提供一个宝贵的研究和教育平台，以培训下一代致力于寻找解决地球上紧迫的可持续性问题的解决办法的跨学科工程师和科学家。

1236691Betenbaugh/BouwerAlgae represent a potentially valuable renewable source of liquid fuels including diesel and jet fuel. These liquid fuels are derived from the lipids generated during the accumulation of algal biomass and represent an alternative to petroleum-based liquid fuels for airplanes and motor vehicles. Algal biomass can be generated using photosynthesis (photoautotrophy), with organic carbon sources (heterotrophy), or using a combination of organic carbon and sunlight (mixotrophy). Unfortunately, algal biofuel processes derived from photosynthesis alone typically generate low amounts of algal biomass and reduced yields of the lipids. Alternatively, algae can generate much higher levels of biomass and produce high lipid yields when supplemented with organic carbon and other nutrients. However, the addition of traditional organic carbon sources such as glucose increases production costs and hinders commercial feasibility. An equally pressing sustainability problem is the environmental impacts and costs resulting from the accumulation and disposal of agricultural, industrial, and municipal organic wastes. This research program will simultaneously address both sustainability and energy issues by combining organic waste treatment processes with the generation of liquid fuels using microalgal bioprocessing. Specifically the project aims to alter waste treatment in order to generate increased amounts of organic carbon sources that can be consumed by microalgae and to manipulate microalgae to enable these hosts to consume a greater variety of carbon sources available from anthropogenic organic wastes. The specific objectives of the project are as follows: 1) Optimize environmental waste processing (fermentation) to generate high yields of organic nutrients that can be consumed by microalgae; 2) Manipulate microalgae genetically in order to allow these cells to consume a larger number of organic waste by-products. In the Bouwer laboratories, organic waste processing conditions including chemical and biological pretreatment steps as well as carbon and nitrogen content will be manipulated in order to increase organic matter conversion to target organic acids. Unfortunately, while microalgae can consume some organic acids, many algae are unable to process other organic acid by-products from waste treatment processes. Therefore, the second aim of the project in the Betenbaugh laboratory is to reprogram microalgae cellular metabolism to enable them to consume additional organic waste by-products that the species do not typically consume. Three of the greatest sustainability challenges facing the world are pollution of the environment, over-reliance on non-renewable fossil fuels, and global warming. Long-term solutions should consider holistic approaches that address multiple sustainability issues simultaneously. This program addresses these challenges by linking organic liquid waste disposal with microalgae growth and lipids production for the generation of renewable liquid biofuels. Utilization of organic wastes by microalgae will reduce agricultural, industrial and domestic waste runoff that threatens our rivers, lakes, and oceans and will lead to the creation of jobs in areas where the employment opportunities are most needed. This technology can integrate with existing agricultural and domestic waste-treatment facilities for renewable energy generation, economic development, and community self-sufficiency. An equally important goal will be the development of a new education paradigm focused on sustainability. Through a partnership with Baltimore's minority public STEM high schools, students will be educated using hands-on approaches to generate biofuels from microalgae in web-based and laboratory settings including a local arboretum. In addition, classroom and laboratory courses focused on bioenergy, biosustainability, and environmental recovery are under development at Johns Hopkins University. Thus, the proposed project will provide a valuable research and education platform to train the next generation of cross-disciplinary engineers and scientists dedicated to finding solutions to pressing sustainability issues on our planet.