CAREER: Micromechanics and Metabolic Properties of Living Interfacial Materials

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。这个学院早期职业发展（Career）奖将支持研究揭示细菌如何在水和油的界面以及水和空气的界面生长和适应。细菌聚集体的膜，也称为生物膜，是微生物生命的一种普遍形式。当它们生长在固液界面时，会引起健康问题，比如关节植入物附近的感染。当生物膜在气液界面生长时，它们会导致肺部问题。生物膜如何在这些界面生长和适应还不是很清楚。这项工作将首先探索细菌如何应对表面张力和能量的变化。接下来，这项工作将研究细菌如何适应不断变化的条件，以创造新的材料。最后，这项工作将提示如何使用病毒和纳米材料来控制流体界面上的细菌发育。这项工作的结果最终将与治疗慢性肺部感染或利用细菌开发更有效的原油泄漏处理方法有关。此外，这些研究活动将激励学生追求STEM职业。该项目将调整专业参与策略，为少数族裔、第一代和经济困难的学生提供大学预科和大学经历。它将促进一种包容的氛围，并通过一系列指导经验促进这些学生的学业成功。教育活动包括“bug as Materials”夏令营、大学申请研讨会和本科生暑期体验。调控生物膜中微生物生长的物理化学机制仍然知之甚少，部分原因是微生物对不同环境条件的反应能力的多样性。更鲜为人知的是控制在流体界面形成的生物膜的生长和代谢反应的机制。为了验证细菌代谢一小块界面并分泌保护性涂层以在恶劣的界面条件下茁壮成长的总体假设，将追求三个目标：(1)系统地阐明界面膜的粘弹性特性和生理学；(2)表征界面约束下细菌的表型适应对界面膜力学的影响；(3)确定化学和生物损伤如何改变混合界面膜的机械完整性。模式生物，包括铜绿假单胞菌和金黄色葡萄球菌，将有助于阐明细菌界面膜是如何形成的，以及如何通过物理、化学和生物损伤改变流变性能。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).This Faculty Early Career Development (CAREER) award will support research to reveal how bacteria grow and adapt at the interface of water and oil, and at the interface of water and air. Films of bacterial aggregates, also called biofilms, are a ubiquitous form of microbial life. When they grow on solid-liquid interfaces, they can cause health problems like infections near joint implants. When biofilms grow at air-liquid interfaces, they can cause lung problems. How biofilms grow and adapt at these interfaces is not well understood. This work will first explore how bacteria cope with changes in surface tension and energy. Next, this work will study how bacteria’s adaptation to changing conditions can be manipulated to create new materials. Finally, this work will suggest how viruses and nanomaterials could be used to control bacterial development at fluid interfaces. The results of this work will ultimately be relevant for treating chronic lung infections or developing more effective treatment of crude oil spills using bacteria. Moreover, these research activities will motivate students to pursue STEM careers. The project will adapt professional engagement strategies to develop pre-college and college experiences for minorities, first-generation, and financially challenged students. It will promote an inclusive climate and facilitate these students’ academic success through a range of mentored experiences. Educational activities include a “Bugs as Materials” Camp, a college application workshop, and a summer experience for undergraduates.The physicochemical mechanisms that regulate microbial growth in biofilms remain poorly understood, in part because of the versatility of microorganisms’ ability to respond to diverse environmental conditions. Even less well-known are the mechanisms governing the growth and metabolic responses of biofilms formed at the fluid interface. To test the overarching hypothesis that bacteria metabolize a patch of an interface and secrete a protective coating to thrive under harsh interfacial conditions, three objectives will be pursued: (1) systematically elucidate the viscoelastic properties and the physiology of interfacial films; (2) characterize the effects of phenotypic adaptation of bacteria under interfacial confinement on interfacial film mechanics; and (3) determine how the mechanical integrity of mixed interfacial films is altered by chemical and biological insults. Model organisms, including Pseudomonas aeruginosa and Staphylococcus aureus, will help elucidate how films at bacterial interfaces form, and how the rheological properties are altered by physical, chemical, and biological insults.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.