Influence of sugars on biofilm formation and composition in E. coli

Biofilms are a collection of microorganisms that are attached to a surface, surrounded by a self-generated substance called extracellular polymeric substance (EPS). Biofilms are an important area of research as they increase an organism’s resistance to antibiotics by slowing diffusion and creating robust microenvironments. Biofilms cause damage in clinical and industrial settings as they are persistent, therefore, understanding and identifying mechanisms that change biofilm abundance and heartiness are of paramount importance. We have observed that biofilm growth in E. coli bacteria can be influenced by the presence of certain sugars using a well-established colorimetric assay. We have recently focused on the changes to biofilm formation that lactose, a disaccharide, induces at certain temperatures and with varying availability of nutrients. When we add saturating amounts of lactose (0.5% w/v) to rich media, we see a significant increase in biofilm formation. To further understand the mechanism of this increase in biofilm growth, we are investigating the composition of the EPS, which is made of several types of biomolecules (e.g., proteins, carbohydrates, lipids, and extracellular DNA) that bacteria excrete when forming biofilms. We will use a variety of stains to quantify these biomolecules using confocal laser scanning microscopy (CLSM) and biochemical assays to determine total carbohydrate and protein concentration found in the EPS