CAREER: Quorum enhanced sustainable treatment of nitrogen (QuEST-N)

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。环境工程师使用微生物处理废水和保护公众健康已有一个世纪之久。生物废水处理(WWT)在生态系统和环境保护中也发挥着重要作用，包括利用硝化和反硝化细菌去除废水中的过量氮并将其转化为无害的氮气。环境元基因组学的进展正在提供关于WWT系统中微生物群落的更详细和更深入的信息。然而，环境工程师和废水处理从业者缺乏策略和工具来利用这些新信息来控制WWT系统中硝化和反硝化细菌群落的结构、组成、功能多样性和代谢途径。这项职业提案的首要目标是利用各种形式的微生物通信信号，通常被称为群体感应(QS)分子，以促进更有效和更可持续的生物膜反应器的设计和运行，用于脱氮。该项目的成功完成将通过产生新的基础知识来促进污水处理厂(WWTP)和水资源回收设施(WRRF)下一代生物脱氮(BNR)工艺的开发和实施，从而造福社会。通过学生教育和培训将进一步造福社会，包括指导霍华德大学的一名博士后、一名研究生和三名本科生。环境微生物学、微生物生态学和环境生物技术的进步为设计和建造下一代生物膜反应器提供了前所未有的机会，以同时去除废水中多余的营养物质(氮和磷)。生物膜反应器使污水处理厂和污水处理厂能够利用有利于生物硝化工艺的缓慢生长的微生物，包括厌氧氨氧化菌(Anammox)和反硝化厌氧甲烷氧化菌(达摩)。然而，下一代生物膜反应器的设计和运行将需要对生物膜微生物生态进行控制，以实现更高效、更经济的废水脱氮。这个职业项目的首要目标是探索使用群体感应(QS)来控制和操纵BNR反应器中使用的细菌生物膜的微生物生态。QS涉及信号分子的产生和释放，这种信号分子被称为自动诱导剂，使细菌群落能够协调它们的行为，包括生物膜的形成。这项研究的指导性假设是，自动诱导剂的存在改变了氮循环细菌的活性，QS可以用来改变哪些生物在生物膜上定居。拟议研究的具体目标是：(1)测试自动诱导剂在富含氮循环细菌的培养中的效果；(2)评估自诱导剂在更复杂的生物膜群落中对氮循环细菌的影响；(3)开发包含QS的生物膜模型；以及(4)评估在膜曝气生物膜反应器中使用自诱导剂分子的控制策略。该项目的成功完成有可能产生变革性的影响，通过产生基础知识来推动在污水处理厂和污水处理厂内开发和部署定额增强型可持续氮处理新工艺(QUEST-N)。为了实现这一职业项目的教育和培训目标，首席调查员将利用她与水环境联合会(WEF)的持续合作，1)在霍华德大学的INFLOW(增加水中的机会)计划中增加研究培训部分，2)将该计划扩展到其他少数群体服务机构(MSI)，以促进STEM教育的多样性，并扩大对水行业劳动力的参与。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Environmental engineers have used microorganisms over a century to treat wastewater and protect public health. Biological wastewater treatment (WWT) also plays a critical role in ecosystem and environmental protection including the use of nitrifying and denitrifying bacteria to remove and convert excess nitrogen from wastewater to harmless nitrogen (N2) gas. Advances in environmental metagenomics are providing more detailed and in-depth information about microbial communities in WWT systems. Yet, environmental engineers and wastewater practitioners lack strategies and tools to leverage this new information to control the structure, composition, functional diversity, and metabolic pathways of nitrifying and denitrifying bacterial communities in WWT systems. The overarching goal of this CAREER proposal is to harness various forms of microbial communication signals, commonly referred to as quorum sensing (QS) molecules, to advance the design and operations of more efficient and sustainable biofilm reactors for nitrogen removal. The successful completion of this project will benefit society through the generation of new fundamental knowledge to advance the development and implementation of next generation biological nitrogen removal (BNR) processes in wastewater treatment plants (WWTPs) and water resource recovery facilities (WRRFs). Further benefits to society will be achieved through student education and training including the mentoring of a post-doctoral fellow, a graduate student, and three undergraduate students at Howard University.Advances in environmental microbiology, microbial ecology, and environmental biotechnology are providing unprecedented opportunities to design and build next generation biofilm reactors for the simultaneous removal of excess nutrients (nitrogen and phosphorus) from wastewater. Biofilm reactors are enabling WWTPs and WRRFs to harness slow growing microorganisms that are advantageous to BNR processes including anaerobic ammonium oxidizers (anammox) and denitrifying anaerobic methane oxidizers (DAMO). However, the design and operation of next generation biofilm reactors for BNR will require the control of the biofilm microbial ecology to achieve more efficient and cost-effective nitrogen removal from wastewater. The overarching goal of this CAREER project is to explore the use of quorum sensing (QS) to control and manipulate the microbial ecology of bacterial biofilms used in BNR reactors. QS involves the generation and release of signaling molecules known as autoinducers that enable bacterial communities to coordinate their behavior including the formation of biofilms. The guiding hypotheses of this research are that the presence of autoinducers changes the activity of nitrogen cycling bacteria and QS can be used to alter which organisms colonize a biofilm. The specific objectives of the proposed research are to: (1) Test the effect of autoinducers in cultures enriched for nitrogen cycling bacteria; (2) Evaluate the effect of autoinducers in nitrogen cycling bacteria in more complex biofilm communities; (3) Develop a biofilm model that incorporates QS; and (4) Evaluate a control strategy that uses autoinducer molecules in a membrane aerated biofilm reactor. The successful completion of this project has the potential for transformative impact through the generation of fundamental knowledge to advance the development and deployment of the new process of quorum enhanced sustainable treatment of nitrogen (QuEST-N) within WWTPs and WRRFs. To achieve the educational and training goals of this CAREER project, the Principal Investigator will leverage her ongoing collaboration with the Water Environment Federation (WEF) to 1) add a research training component to the InFLOW (Increasing Opportunities in Water) program at Howard University and 2) expand the program to other minority serving institutions (MSI) to advance diversity in STEM education and broaden participation in the water industry workforce.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.