CAREER: Predicting Biofilm-Bound Sediment Dynamics Through Multiscale Experiments

职业：通过多尺度实验预测生物膜结合的沉积物动力学

• 批准号: 2236497
• 负责人: Judy Yang
• 金额: $ 65.31万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2028-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2236497&HistoricalAwards=false
• 关键词: CAREER; Predicting; Biofilm; Bound; Sediment

Sediment transport is a key process controlling coastal and riverine erosion, which costs the U.S. billions of dollars per year. Most natural sediment, such as mud and fine sand, inevitably harbors microbial biofilms. Biofilms have been shown to alter the threshold and rate of sediment transport by up to 40-fold. However, predictive sediment transport equations that account for the impacts of biofilms are lacking. A key challenge in developing such predictive equations is that the transport of sediment at macroscale ( 1 m) is controlled by biofilms at micro (10^-6 to 10^-3 m) to mesoscale (10^-3 to 10^-1 m). This study aims to combine micro- to mesoscale flow-cell and imaging technology with macroscale flume experiments to quantify the impacts of micro- to mesoscale biofilms on macroscale sediment transport. Predictive equations for biofilm-bound sediment transport will be developed. The results of this study will help improve predictions of coastal and riverine erosion, which will guide future coastal and riverine restoration projects, and support better predictions and control of the spread of biofilm-bound particulate contaminants. In addition, multiscale hands-on educational activities based on the proposed research will be developed and integrated into teaching, mentoring, K12 education, and public outreach. These activities will introduce the essence of the research to a diverse range of young learners, including female and Native American students. The goal of the proposed research is to (1) quantify the impacts of sediment size and hydrodynamic conditions on the properties of micro- to mesoscale biofilms on sediment surfaces; (2) predict the macroscale transport of suspended microscale biofilm-sediment aggregates; (3) predict the onset of bedload transport for sediment covered with mesoscale biofilm mats. Systematically controlled experiments with submicron resolution confocal microscopic imaging will be conducted in microfluidic flow cells to visualize and quantify the development of micro- to mesoscale biofilms on sediment surfaces and the formation of biofilm-sediment aggregates. Flume experiments combined with digital imaging, tensile tests, rheometer measurements, hydrodynamic measurements, and topographic measurements will be conducted to quantify the impacts of biofilms with varying morphological and rheological properties on macroscale sediment transport. The results from both microfluidic and flume experiments will be used to develop predictive equations for the transport of suspended biofilm-sediment aggregates and biofilm mat-covered bedload.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.

泥沙输送是控制海岸和河流侵蚀的关键过程，每年给美国造成数十亿美元的损失。大多数天然沉积物，例如泥土和细沙，不可避免地含有微生物生物膜。生物膜已被证明可以将沉积物运输的阈值和速率改变高达 40 倍。然而，缺乏考虑生物膜影响的预测沉积物输送方程。开发此类预测方程的一个关键挑战是，宏观尺度（1 m）沉积物的传输是由微观尺度（10^-6 至 10^-3 m）到中尺度（10^-3 至 10^-1）的生物膜控制的。米）。本研究旨在将微尺度到中尺度流动池和成像技术与宏观水槽实验相结合，以量化微尺度到中尺度生物膜对宏观沉积物迁移的影响。将开发生物膜结合沉积物迁移的预测方程。这项研究的结果将有助于改进对沿海和河流侵蚀的预测，从而指导未来的沿海和河流恢复项目，并支持更好地预测和控制生物膜结合颗粒污染物的扩散。此外，基于拟议研究的多尺度实践教育活动将被开发并整合到教学、指导、K12 教育和公共宣传中。这些活动将向包括女性和美国原住民学生在内的各种年轻学习者介绍研究的精髓。拟议研究的目标是（1）量化沉积物尺寸和水动力条件对沉积物表面微到中尺度生物膜特性的影响； (2) 预测悬浮微尺度生物膜-沉积物聚集体的宏观迁移； (3) 预测覆盖有中尺度生物膜垫的沉积物的床质迁移的开始。将在微流体流动池中进行亚微米分辨率共焦显微成像的系统控制实验，以可视化和量化沉积物表面上微米到中尺度生物膜的发展以及生物膜沉积物聚集体的形成。将进行水槽实验与数字成像、拉伸测试、流变仪测量、流体动力学测量和地形测量相结合，以量化具有不同形态和流变特性的生物膜对宏观沉积物迁移的影响。微流体和水槽实验的结果将用于开发悬浮生物膜沉积物聚集体和生物膜垫覆盖的床质输送的预测方程。该奖项反映了 NSF 的法定使命，并通过使用基金会的知识进行评估，被认为值得支持。优点和更广泛的影响审查标准。

项目成果

Microfluidic investigation of the impacts of flow fluctuations on the development of Pseudomonas putida biofilms

流量波动对恶臭假单胞菌生物膜发育影响的微流控研究

• DOI: 10.1038/s41522-023-00442-z
• 发表时间: 2023-10-03
• 期刊: npj Biofilms and Microbiomes
• 影响因子: 9.2
• 作者: Wei, Guanju;Yang, Judy Q.
• 通讯作者: Yang, Judy Q.