Excellence in Research: Harnessing Microbial Signals for Biofilm Control

城市化增加了处理废水的需求。在美国，这种需求通常是通过在水资源回收设施（WRRFs）中处理水来满足的。许多wrrf采用附着生长生物膜反应器，其中有益微生物生长在固体表面的薄层中。生物膜反应器非常适合于拥挤的城市地区，因为它们可以在不增加空间需求的情况下提高WRRF的处理效率。生物膜反应器在一组狭窄的条件下最有效地运行。如果生物膜太厚，微生物生长就会变慢，从而降低工艺效率。本研究的目的是通过测量微生物产生的信号分子来开发控制生物膜的方法。这些信息将用于开发生物膜控制策略，以优化处理。本研究结果将有助于揭示废水处理中的微生物信号系统。这些知识也将有助于了解如何控制医疗设备、牙齿和其他系统中的其他生物膜系统。该项目带来的社会效益包括对当地K-12学校的废水处理进行教育和推广，以及对霍华德大学代表性不足的学生进行教育，从而增加了美国STEM劳动力的多样性和科学素养。附着式生物膜反应器是城市水资源回收设施的理想选择，因为它可以在不增加反应器尺寸的情况下提高处理率。生物膜反应器的其他潜在好处包括提高过程稳定性和保留系统中生长缓慢的生物。生物膜反应器的高效运行需要控制生物膜的厚度和功能。生物膜中的微生物群落利用化学信号分子协调群落功能。虽然微生物信号分子在几十年前就被发现了，但人们对控制这些分子在环境中表达的能力仍然知之甚少。本研究的目的是利用各种形式的微生物通信信号来控制生物膜系统。这将通过以下方式实现：(1)确定全尺寸wrrf中信号分子的类型和丰度；(2)在纯培养生物膜中建立信号分子生物膜调控策略；(3)在环境相关的混合生物膜培养中实施基于信号分子的控制策略。WRRF微生物群落的高通量测序分析将用于确定不同信号系统的遗传潜力。信号分子也将在华盛顿特区现有的wrrf中进行测量，这些wrrf采用不同的工艺配置。全面的wrrf研究将为在纯培养生物膜和实验室规模的混合培养硝化生物膜中使用信号分子进行生物膜控制提供策略。这项研究的影响将超出wrrf的范围，并为饮用水分配系统和医院环境提供潜在的好处，在这些环境中，生物膜管理是保护公众健康所必需的。研究结果将纳入现有的K-12外展活动。这项研究将支持来自霍华德大学的女性和代表性不足的研究生和本科生，并将有利于早期职业PI，该PI致力于为代表性不足的群体创造学习微生物学和环境工程的机会。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。

Urbanization increases the need to treat wastewater. In the United States, this demand is typically met by treating water in water resource recovery facilities (WRRFs). Many WRRFs employ attached growth biofilm reactors where beneficial microorganisms grow in a thin layer on solid surfaces. Biofilm reactors are well suited for crowded urban locations because they can increase WRRF treatment efficiency without increasing space demands. Biofilm reactors operate most efficiently under a narrow set of conditions. If the biofilm is too thick, microorganisms will grow slower, thus decreasing process efficiency. The goal of this research is to develop ways to control biofilms by measuring signaling molecules produced by the microorganisms. This information will be used to develop a biofilm control strategy for treatment optimization. The results of this research will shed light on microbial signaling systems in wastewater treatment. This knowledge will also help understand how to control other biofilm systems in medical devices, on our teeth, and in other systems. Benefits to society resulting from this project include education and outreach on wastewater treatment to local K-12 schools and the education of underrepresented students at Howard University, thus increasing the diversity and scientific literacy of the Nation’s STEM workforce.Attached growth biofilm reactors are ideally suited for the urban water resource recovery facilities (WRRFs) because the rate of treatment can increase without a corresponding expansion in reactor size. Additional potential benefits of biofilms reactors include improved process stability and retention of slow growing organisms in the system. Efficient operation of biofilm reactors requires control of biofilm thickness and function. Microbial communities in biofilms use chemical signaling molecules to coordinate community function. While microbial signaling molecules were discovered decades ago, the ability to control expression of these molecules in the environment is still poorly understood. The goal of this research is to harness various forms of microbial communication signals to control biofilm systems. This will be achieved by: (1) determining the type and abundance of signaling molecules in full-scale WRRFs; (2) establishing a signaling molecule biofilm control strategy in pure culture biofilms; and (3) implementing this signaling molecule based control strategy in environmentally relevant mixed biofilm cultures. High throughput sequencing analysis of WRRF microbial communities will be used to determine the genetic potential for different signaling systems. Signaling molecules will also be measured in existing WRRFs in the Washington, DC region operating distinct process configurations. Studies of full-scale WRRFs will inform strategies for using signaling molecules for biofilm control in pure culture biofilms and in a lab-scale mixed culture nitrifying biofilm. The implications of this research will extend beyond WRRFs and offer potential benefits to drinking water distribution systems and hospital environments, where biofilm management is necessary to protect public health. Research results will be integrated into existing K-12 outreach activities. This research will support female and underrepresented graduate and undergraduate students from Howard University and will benefit an early career PI that is committed to creating opportunities for underrepresented groups to learn about microbiology and environmental engineering.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.