Yang Research Group

Interactions between biofilm, flow and sediment transport

Background

Biofilms are consortiums of bacterial cells stick together by extracellular polymeric substances (EPSs). Biofilms can increase pathogenic contamination of drinking water, cause biofilm-related diseases, and alter the rate of sediment erosion in rivers and coasts. Meanwhile, some biofilms have been used for degrading polycyclic aromatic hydrocarbons (PAHs), enhancing oil recovery efficiency, and removing excess nutrients and contaminants from wastewater. Fundamental understandings of physical factors that control biofilm formation are needed yet currently lacking.

Goal

Our goal is to systematically study the interactions between biofilm, flow, and sediment transport, focusing on the effects of flow shear stress, different flow patterns, and surface properties on the biofilm formation process. We are also interested in the biofilm's ability to bind sediment particles and its effects on sediment transport. We will create equations to predict the formation of biofilms under varying flow conditions. The results can be used in industrial, medical, and scientific fields to control biofilm growth.

Method

We use microfluidic experiments, confocal imaging, numerical simulations, and mathematical modeling to study the interactions between biofilm, flow, and sediment transport. We developed imaging analysis methods using Image-J and Matlab to calculate the biofilm thickness, biofilm shape, and biofilm structure in an effort to demonstrate the effects of flows on biofilm growth.

Publications

Wei, G., & Yang, J. Q. (2023). Impacts of hydrodynamic conditions and microscale surface roughness on the critical shear stress to develop and thickness of early-stage Pseudomonas putida biofilms. Biotechnology and Bioengineering, 1– 12.
Wei, G., & Yang, J. Q. (2023). Microfluidic investigation of the impacts of flow fluctuations on the development of Pseudomonas putida biofilms. npj Biofilms and Microbiomes, 9 , 73.