Understanding the role of lactose, glucose, and galactose on E. coli biofilm growth, composition, and antibiotic sensitivity

Location

Bent Corridor, Science Center

Document Type

Poster - Open Access

Start Date

5-1-2026 12:00 PM

End Date

5-1-2026 2:00 PM

Research Program

The National Science Foundation (MCB 2226953)

Abstract

Bacterial cells can be present in a mobile, single-celled planktonic state or a sessile, biofilm state where cells group together, adhere to surfaces, and rely on shared resources for survival. This biofilm state is observed during periods of environmental stress and allows bacteria to exhibit increased antibiotic resistance. Documenting the influence of sugar metabolism on biofilm growth, composition, and antibiotic sensitivity provides insight into environmental conditions that modulate biofilm growth. Specifically, we focused on the impact of lactose, a non-phosphotransferase disaccharide that utilizes a separate, controlled pathway for uptake into the bacterial cell, on biofilm growth, composition, and antibiotic sensitivity in Escherichia coli (E. coli). We investigated whether the monosaccharides comprising lactose, glucose and galactose, influence biofilm growth similarly to lactose, both collectively and independently. Biofilm growth was quantified through lawn and colony growth. Additionally, disk diffusion, microbroth dilutions, and colony growth were carried out with different classes of antibiotics, fluoroquinolones and an antimycobacterial agent, to quantify changing susceptibility. For norfloxacin, the minimum inhibitory concentration is greater for glucose and galactose, separately and combined, compared to lactose, a result corroborated in disk diffusion assays. Knowledge about the intersection and influence of sugar metabolism, biofilm formation and composition, and antibiotic susceptibility will improve strategies to disrupt biofilm formation, allowing for better control of associated infections and a greater understanding of antibiotic resistance mechanisms.

Keywords:

Biofilm, Sugar, E. coli, Antibiotic sensitivity

Notes

Presenter: Molly Foley

Major

Biochemistry; Horn Performance

Award

Research Corporation for Science Advancement Cottrell Scholar Award

Project Mentor(s)

Lisa Ryno, Chemistry and Biochemistry

2026

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May 1st, 12:00 PM May 1st, 2:00 PM

Understanding the role of lactose, glucose, and galactose on E. coli biofilm growth, composition, and antibiotic sensitivity

Bent Corridor, Science Center

Bacterial cells can be present in a mobile, single-celled planktonic state or a sessile, biofilm state where cells group together, adhere to surfaces, and rely on shared resources for survival. This biofilm state is observed during periods of environmental stress and allows bacteria to exhibit increased antibiotic resistance. Documenting the influence of sugar metabolism on biofilm growth, composition, and antibiotic sensitivity provides insight into environmental conditions that modulate biofilm growth. Specifically, we focused on the impact of lactose, a non-phosphotransferase disaccharide that utilizes a separate, controlled pathway for uptake into the bacterial cell, on biofilm growth, composition, and antibiotic sensitivity in Escherichia coli (E. coli). We investigated whether the monosaccharides comprising lactose, glucose and galactose, influence biofilm growth similarly to lactose, both collectively and independently. Biofilm growth was quantified through lawn and colony growth. Additionally, disk diffusion, microbroth dilutions, and colony growth were carried out with different classes of antibiotics, fluoroquinolones and an antimycobacterial agent, to quantify changing susceptibility. For norfloxacin, the minimum inhibitory concentration is greater for glucose and galactose, separately and combined, compared to lactose, a result corroborated in disk diffusion assays. Knowledge about the intersection and influence of sugar metabolism, biofilm formation and composition, and antibiotic susceptibility will improve strategies to disrupt biofilm formation, allowing for better control of associated infections and a greater understanding of antibiotic resistance mechanisms.