Bioprocess Engineering to Harness the Potential of Phototrophic Organisms to Convert Wastes into Value Added Products

走向更加循环的经济将是应对气候变化的解决方案的一部分，这将需要能够将二氧化碳转化为有用产品(例如燃料、化学品、食品)的技术。利用光养生物有很大的潜力，因为它们在用太阳能固定二氧化碳方面非常有效。特别是，微藻、蓝藻和紫色细菌等光养微生物具有巨大的前景，因为它们可以比植物生长得更快，利用废水获取养分，并在非耕地上生长。在工业规模上实现光营养微生物的潜力，需要开发在开放(非无菌)系统中强大的过程，利用太阳能，并提供足够集中的产品，以促进有效的下游回收。基于生物膜的系统解决了当前光敏技术中的一些瓶颈，但除了废水处理应用之外，很少受到关注。因此，这项研究的长期目标是促进我们对基于光生生物膜系统的理解，并开发强大的过程，将废物(如废水、二氧化碳)转化为有用的产品，如化学积木、燃料、食品和营养食品。在接下来的五年里，我们将致力于三个方面的工作：1)考虑生物膜和悬浮阶段，工程变量和物理化学因素对生物膜生物反应器组成和生产率的影响；2)设计生物膜光生物反应器，以改善光和二氧化碳的输送；以及3)开发基于生物膜的系统，以生产增值产品。这项研究将极好地利用生物地带的独特能力，这是多伦多大学的一个创新的协作生物工程研究和教育设施。总体而言，这项研究将有助于加拿大从资源经济向技术驱动的循环生物经济转型。此外，提高我们对对环境有益并生产有价值产品的生物系统的理解将支持加拿大成为可持续技术的领导者。在这个过程中，学生将发展高水平的批判性思维和沟通技能的科学和工程及其应用。这种培训将使他们能够在可持续发展背景下不断增长的化学、生物工艺和环境工程领域的工业或学术界拥有有价值的职业。

Moving towards a more circular economy will be part of the solution to address climate change and this will require technologies that can convert CO2 into useful products (e.g., fuels, chemicals, foods). There is significant potential to use phototrophic organisms since they are exceptionally effective at fixing CO2 with solar energy. In particular, phototrophic microorganisms such as microalgae, cyanobacteria and purple bacteria hold tremendous promise because they can grow faster than plants, use wastewaters for nutrients and be grown on non-arable land. Realizing the potential of phototrophic microorganisms at industrial scales requires the development of processes that are robust in open (nonsterile) systems, make use of solar energy, and that provide products that are sufficiently concentrated to facilitate effective downstream recovery. Biofilm-based systems address some of the bottlenecks in current phototroph technology but have received little attention beyond wastewater treatment applications. Thus, the long-term goal of this research is to advance our understanding of phototroph biofilm-based systems and develop robust processes that can convert wastes (e.g., wastewater, CO2) into useful products such as chemical building blocks, fuel, food and nutraceuticals. In the next five years we will work on three areas: 1) the impact of engineering variables and physicochemical factors on the composition and productivity in biofilm bioreactors considering the biofilm and suspension phases; 2) Design biofilm photobioreactors to improve light and CO2 delivery; and 3) Develop biofilm-based systems to produce value-added products. The research will make excellent use of the unique capabilities of BioZone, an innovative collaborative bioengineering research and educational facility at the University of Toronto. Overall, this research will contribute to Canada's transition from a resource economy to a technology-driven, circular bioeconomy. Furthermore, improving our understanding of biological systems that are benign to the environment and produce valuable products will support Canada in becoming a leader in sustainable technologies. In the process, students will develop high-level critical thinking and communication skills of the science and engineering and its application. This training will enable them to have rewarding careers in industry or academia in the growing areas of chemical, bioprocess and environmental engineering in the context of sustainable development.