Collaborative Research: Shedding Light on The Microbial Ecologyand Ecophysiology of Electroactive Anammox Communities

合作研究：揭示电活性厌氧氨氧化群落的微生物生态学和生态生理学

• 批准号: 2327515
• 负责人: Heyang Yuan
• 金额: $ 27万
• 依托单位: Temple University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2327515&HistoricalAwards=false
• 关键词: Collaborative; Research; Shedding; Light; Microbial

Wastewater treatment plants (WWTPs) play a critical role in environmental protection. In the United States, municipal WWTPs process billions of gallons of wastewater every day to remove suspended solids, organic matter, and excess nitrogen nutrients such as ammonium. In most municipal WWTPs, a biological process, activated sludge (AS), is used to remove nitrogen by coupling an aerobic nitrification process which oxidizes ammonium into nitrate followed by an anaerobic denitrification process that reduces the nitrate to benign dinitrogen gas (N2). However, ammonium nitrification in AS reactors requires the supply of oxygen using aeration which requires a significant amount of energy and accounts for 70-80 % of the total energy used in WWTPs. Anaerobic ammonium oxidation (anammox) has emerged as a promising microbial process for removing nitrogen from municipal wastewater with lower energy consumption and operating costs. However, the selection, cultivation, and integration of anammox bacteria into reactors and the treatment trains of municipal WWTPs has remained a challenge due to their slow growth rates and competition from other microorganisms including ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB). Recent studies show that anammox microbes can generate electricity. Building upon these promising studies, the Principal Investigators (PIs) of this project propose to explore the selection of electroactive anammox bacteria using bioelectrochemical systems with the goal of accelerating their growth, proliferation, and stability in municipal wastewater. The successful completion of this project will benefit society through the generation of fundamental knowledge in environmental microbiology and biotechnology to advance the development and deployment of more cost-effective solutions for nitrogen removal from municipal and industrial wastewater. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student at Temple University and one graduate student at the University of Maryland.Anaerobic ammonium oxidation (anammox) bacteria have recently been shown to perform extracellular electron transfer (EET), but little is known about the mechanisms through which anammox bacteria transfer electrons extracellularly to electrodes, and even less is known about how electrons are transported intracellularly from the anammoxosome to the outer membrane proteins for downstream EET. The overarching goal of this project is to advance the fundamental understanding of the microbial ecology and ecophysiology of electroactive anammox communities in bioelectrochemical systems (BES). The core and guiding hypothesis of the proposed research is that in BES, EET-dependent anammox is carried out by a microbial population composed of electroactive anammox bacteria and their electroactive partners. Together they form a mutualistic relationship: anammox bacteria fix carbon dioxide and provide organic matter to electroactive bacteria, whose electron shuttles are scavenged by anammox bacteria for EET. If the hypothesis holds, EET-dependent anammox could be electrochemically enhanced through the enrichment of those two partners. The specific aims of the research are to 1) develop electrochemical strategies to build electroactive anammox communities; 2) understand the microbial interactions in electroactive anammox communities; and 3) elucidate the metabolic pathways involved in EET-dependent anammox. The successful completion of this project has the potential for transformative impact through the generation of new fundamental knowledge on the microbial ecology and ecophysiology of electroactive anammox microbiomes in BES to guide the design and implementation of more sustainable technologies and solutions to remove nitrogen from municipal and industrial wastewater. To implement the education and training goals of the project, the PIs propose to leverage existing programs at Temple University (TU) and the University of Maryland (UMD) to recruit and mentor undergraduate students from underrepresented groups to work on the project. In addition, the PIs plan to integrate the findings from this research into existing environmental engineering graduate/undergraduate courses at TU and UMD.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.

废水处理厂（WWTP）在环境保护中发挥着至关重要的作用。在美国，市政污水处理厂每天处理数十亿加仑的废水，以去除悬浮固体、有机物和过量的氮营养物（如铵）。在大多数城市污水处理厂中，采用生物工艺——活性污泥（AS），通过耦合好氧硝化工艺（将铵氧化成硝酸盐）和厌氧反硝化工艺（将硝酸盐还原成无害的二氮气体（N2））来脱氮。然而，AS反应器中的铵硝化需要通过曝气来供应氧气，这需要大量的能量，占污水处理厂总能量的70-80%。厌氧氨氧化（anammox）已成为一种很有前景的微生物工艺，可从城市废水中去除氮，且能耗和运营成本较低。然而，由于厌氧氨氧化菌生长速度缓慢以及来自其他微生物（包括铵氧化菌（AOB）和亚硝酸盐氧化菌（NOB））的竞争，厌氧氨氧化菌的选择、培养以及将其集成到城市污水处理厂的反应器和处理系统中仍然是一个挑战。 。最近的研究表明厌氧氨氧化微生物可以发电。在这些有前途的研究的基础上，该项目的主要研究人员 (PI) 建议探索使用生物电化学系统选择电活性厌氧氨氧化细菌，以加速其在城市废水中的生长、增殖和稳定性。 该项目的成功完成将通过产生环境微生物学和生物技术的基础知识，推动开发和部署更具成本效益的城市和工业废水脱氮解决方案，造福社会。通过学生教育和培训，包括指导天普大学的一名研究生和马里兰大学的一名研究生，将给社会带来额外的好处。厌氧氨氧化（anammox）细菌最近被证明可以进行细胞外电子转移（EET） ），但人们对厌氧氨氧化细菌将电子从细胞外转移到电极的机制知之甚少，更不知道电子如何在细胞内从厌氧氨氧化体转移到外膜蛋白用于下游 EET。该项目的总体目标是增进对生物电化学系统（BES）中电活性厌氧氨氧化群落的微生物生态学和生态生理学的基本理解。该研究的核心和指导性假设是，在 BES 中，EET 依赖的厌氧氨氧化是由电活性厌氧氨氧化细菌及其电活性伙伴组成的微生物群体进行的。它们共同形成一种互惠关系：厌氧氨氧化细菌固定二氧化碳并向电活性细菌提供有机物，电活性细菌的电子穿梭机被厌氧氨氧化细菌清除以获得EET。如果这一假设成立，那么依赖 EET 的厌氧氨氧化可以通过这两个伙伴的富集以电化学方式得到增强。研究的具体目标是1）开发电化学策略来构建电活性厌氧氨氧化群落； 2）了解电活性厌氧氨氧化群落中微生物的相互作用； 3) 阐明 EET 依赖性厌氧氨氧化所涉及的代谢途径。该项目的成功完成有可能产生变革性影响，通过产生关于 BES 中电活性厌氧氨氧化微生物组的微生物生态学和生态生理学的新基础知识，指导设计和实施更可持续的技术和解决方案，以去除市政和工业中的氮。废水。为了实现该项目的教育和培训目标，PI 建议利用坦普尔大学 (TU) 和马里兰大学 (UMD) 的现有项目来招募和指导来自代表性不足群体的本科生来参与该项目。此外，PI 计划将这项研究的结果整合到 TU 和 UMD 现有的环境工程研究生/本科生课程中。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。