The use of an engineered biofilm to prevent undesired biofouling in membrane systems offers a novel approach to addressing a fundamental problem faced in water purification. The goal of this project was to determine the efficacy of this beneficial biofilm model when used as a treatment for established biofilms rather than as a preventative measure. The ability of the engineered strain of E. coli to displace and replace an established biofilm was investigated via 96-well crystal violet assays, dead-end filtration tests, and SEM imaging. It was found that application of the beneficial strain after fouling had occurred only resulted in further fouling, and that the beneficial strain was unable to outperform the control strain when growing in a competitive environment. Future work may show that the model can be used to displace less-aggressive foulants. At present, however, the beneficial biofilm is only effective when formed in advance of fouling, and cannot be used to remove an established biofilm.
