Excellence in Research: Harnessing Microbial Signals for Biofilm Control

城市化增加了污水处理的需求。在美国，这种需求通常通过水资源回收设施(WRRF)中的水处理来满足。许多WRRF使用附着式生长生物膜反应器，其中有益的微生物在固体表面的薄层中生长。生物膜反应器非常适合拥挤的城市地点，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。生物膜反应器在有限的条件下运行效率最高。如果生物膜太厚，微生物生长会变慢，从而降低工艺效率。这项研究的目标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。这些信息将被用来制定生物膜控制策略，以优化处理。这项研究的结果将为废水处理中的微生物信号系统提供参考。这些知识还将有助于理解如何控制医疗器械、牙齿和其他系统中的其他生物膜系统。该项目给社会带来的好处包括对当地K-12学校的污水处理教育和推广，以及在霍华德大学对未被充分代表的学生进行教育，从而增加国家STEM工作人员的多样性和科学素养。附着式生长生物膜反应器非常适合城市水资源回收设施(WRRF)，因为在不相应扩大反应器规模的情况下，处理率可以提高。生物膜反应器的其他潜在好处包括提高工艺稳定性和在系统中保留生长缓慢的生物体。生物膜反应器的高效运行需要控制生物膜厚度和功能。生物膜中的微生物群落使用化学信号分子来协调群落功能。虽然微生物信号分子在几十年前就被发现了，但对这些分子在环境中表达的控制能力仍然知之甚少。这项研究的目的是利用各种形式的微生物通讯信号来控制生物膜系统。这将通过：(1)在全规模的WRRF中确定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控制策略；以及(3)在与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。信号分子还将在华盛顿特区运行不同工艺配置的现有WRRF中进行测量。对全尺寸WRRF的研究将为在纯培养生物膜和实验室规模混合培养硝化生物膜中使用信号分子控制生物膜的策略提供参考。这项研究的影响将延伸到WRRF之外，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，生物膜管理对于保护公众健康是必要的。研究成果将纳入现有的K-12外联活动。这项研究将支持霍华德大学的女性和代表性不足的研究生和本科生，并将使致力于为代表性不足的群体创造机会学习微生物学和环境工程的早期职业PI受益。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。

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.