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

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。一个多世纪以来，环境工程师一直在使用微生物来处理废水，保护公众健康。生物废水处理（WWT）在生态系统和环境保护中也起着至关重要的作用，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（N2）气体。环境宏基因组学的进展正在为污水处理系统中微生物群落提供更详细和深入的信息。然而，环境工程师和废水从业者缺乏策略和工具来利用这些新信息来控制污水处理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。本次CAREER提案的总体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，以推进更有效和可持续的生物膜反应器的设计和运行，以去除氮。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（WWTPs）和水资源回收设施（WRRFs）中下一代生物脱氮（BNR）工艺的开发和实施，从而造福社会。进一步的社会效益将通过学生教育和培训来实现，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，可以同时去除废水中的过量营养物质（氮和磷）。生物膜反应器使污水处理厂和wrrf能够利用对BNR工艺有利的缓慢生长的微生物，包括厌氧氨氧化剂（anammox）和反硝化厌氧甲烷氧化剂（DAMO）。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。本CAREER项目的总体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涉及被称为自诱导剂的信号分子的产生和释放，使细菌群落能够协调其行为，包括生物膜的形成。本研究的指导假设是，自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定植在生物膜上。本研究的具体目的是：(1)测试自诱导剂在氮循环细菌培养物中的作用；(2)在更复杂的生物膜群落中评价自诱导剂对氮循环细菌的作用；(3)建立包含QS的生物膜模型；(4)评价在曝气生物膜反应器中使用自诱导分子的控制策略。该项目的成功完成将产生变革性的影响，通过产生基础知识来推进污水处理厂和水处理厂中氮的群体增强可持续处理（QuEST-N）新工艺的开发和部署。为了实现这个职业项目的教育和培训目标，首席研究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“增加水的机会”项目中增加一个研究培训部分，2)将该项目扩展到其他少数民族服务机构（MSI），以促进STEM教育的多样性，扩大水行业劳动力的参与。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.