Researcher(s)
- Kathryn Hart, Chemical Engineering, University of Delaware
Faculty Mentor(s)
- Alexandra Bayles, Chemical and Biomolecular Engineering, University of Delaware
Abstract
Biofilms have been, and are becoming, increasingly prevalent due to their importance of protecting and enhancing microbial cells and, in turn, supporting applications such as promoting plant growth, improving digestive health and contributing to clean energy via microbial fuel cells. However, natural biofilm characteristics depend heavily on the environment; therefore, it is difficult to understand the functions and development of microbial cells without spatial control. Currently, agar plates or liquid growth media are used to grow cells and biofilms in laboratory settings. Biofilms have both solid and liquid characteristics, making current methods insufficient in replicating biofilm conditions. Therefore, a biofilm mimetic that encapsulates both solid and liquid behavior is necessary to study microbial functions in their native environments. Consequently, poly(acrylic acid) (PAA) was selected to mimic biofilms, as it can be cross-linked to form a gel-like structure that enhances its mechanical properties, similar to a biofilm’s extracellular matrix. We can hydrate and ionize PAA using different media and bases that best suit each cell culture, creating a hydrogel that can house various bacteria. We developed different PAA formulations with compatible bacteria in mind. PAA was hydrated with various growth media and then swelled with various bases to a desired pH. We measured each hydrogel formulation’s rheological properties to confirm similar viscoelastic properties to those of biofilms. The next step would be to add the respective bacterial cells and determine their growth and change in rheology of the PAA medium over the growth period. If bacterial growth is confirmed, these hydrogel formulations can serve as a mimetic biofilm to further study microbial cells in their native environments for various applications.