Date of Award


Document Type


Degree Name

Bachelor of Science


Biochemistry & Molecular Biol.

First Advisor

Dominique Williams


Biofilms are communities of surface-attached bacterial cells encased in an exopolymeric matrix. In this state, they are more resistant to antimicrobial treatment and can have adverse effects in medical, agricultural, and industrial settings. Whereas, as biocatalysts, biofilms from nonpathogenic bacteria enhance their performance and stability in catalysis. Unfortunately, there are several challenges when using bacteria in organic transformations due to their complex cellular chemistry. Trivalent lanthanide metals were discovered to serve regulatory roles in some bacterial catalytic processes, including those of Pseudomonas putida KT2440 (P. putida), a non-infectious Gram-negative bacterium. The main goal of our research is to use cerium(III) to control the adhesion, viability, and activity of P. putida to improve biocatalysis. In our studies, we investigated how Ce(III) influences biofilm formation, in addition to how it influences planktonic cell growth in the presence of toxic levels of the aromatic compound catechol. Crystal violet binding assay was used to assess biofilm formation, and a cell growth assay and colony forming unit analysis were used to assess planktonic cell growth and cell viability. Our studies demonstrated that Ce(III) improved biofilm formation, and it improved planktonic cell growth and cell viability in the presence of catechol with glucose as the carbon source. When glucose was replaced with citrate, preferential biofilm formation and planktonic cell growth was not observed in P. putida with Ce(III). Thus, Ce(III) promoted biofilm growth, planktonic cell growth, and cell viability, and was dependent on the carbon source used to aid growth. We further investigated how Ce(III) influences the depletion of benzoate in catalysis.