(153d) Polymer Surface Dissection for Characterization of Early Colonizing Microbes on Membrane Interfaces

Multispecies biofilms often develop over membrane surfaces in bioseparation systems, leading to membrane clogging and failure. This complex, multi-cellular assembly process is poorly understood from a mechanistic standpoint, in part due to the limited number of tools available for characterizing the cell-cell and cell-surface interactions that occur. Here, we report a high-resolution, materials-based approach for investigating spatiotemporal aspects of biofilm formation. The approach, termed Polymer Surface Dissection (PSD) relies on photodegradable polyethylene glycol (PEG) hydrogels to remove and isolate bacteria that are attached to membrane surfaces at different points in the fouling process for their molecular characterization. Hydrogels are functionalized with bio-affinity ligands to lift microbes off of membrane surfaces following contact. Subsequent exposure of detached cells within the hydrogels to patterned UV light enables their release into solution for retrieval, DNA extraction and 16S amplicon sequencing. The optimized PSD approach enables culture-free identification of membrane-bound colonies at areas as low as 2000 micron². With this approach, we investigate spatiotemporal aspects of biofouling from wastewater communities over PVDF membranes. Specifically, we identify sub-communities of microbes that are early colonizers on these membrane surfaces. As early-colonizing microbes initiate and accelerate the biofouling process, their identification will inform treatment strategies that can extend membrane lifetimes.