Biofilm is a natural state in which bacteria form surface-associated microcolonies surrounded by extracellular polymeric substance (EPS). The dense EPS matrix consists of carbohydrates, proteins, fatty acids, and other biomolecules that contribute to the structural integrity of the biofilm and confer antibiotic resistance in associated bacteria. The antibiotic-resistant nature of biofilms pose a key challenge to public healthcare and agriculture. To investigate the relationship between environmental nutrients on biofilm formation, we are studying the influence of the sugar rhamnose on E. coli biofilm. Rhamnose is an environmentally abundant, major nutrient source that enters cellular metabolism using a unique transport system. Since biofilm cells express certain genes at different levels compared to planktonic cells, we will determine the influence of rhamnose on gene expression in both physical states. We used quantitative polymerase chain reaction (qPCR) to measure E. coli gene expression under three conditions: 0%, 0.1% and 0.5% (w/v) rhamnose. We found that in response to rhamnose, planktonic cells increased the expression of genes involved in biofilm formation, carbohydrate metabolism, and EPS production. In contrast, biofilm cells increased the expression of genes involved in rhamnose metabolism and stress response and decreased expression of genes involved in biofilm formation. To investigate the influence of rhamnose on the entire E. coli transcriptome, we obtained RNA-seq transcriptomic data for 0% and 0.5% (w/v) rhamnose treated samples at 28 °C and 37 °C. Our preliminary analysis reveals a number of diverse processes regulating cellular homeostasis and carbohydrate metabolism that are significantly upregulated regardless of culture temperature. Moving forward, we are conducting further analysis of our transcriptomic data to catalog the full set of genes influenced by rhamnose under varying experimental conditions.

Transcriptomic analysis of rhamnose treatment on E. coli planktonic and biofilm cells

Where thousands of chemistry professionals meet to share ideas and advance scientific and technical knowledge. Spring 2023 abstracts, posters, and presentations will launch at the end of March.

ACS Spring 2023

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.