PhD Scientific Days 2026

Poster Session 3.U - Molecular Medicine

Impact of Simulated Microgravity on E. Coli - T7 Bacteriophage Interactions

Name of the presenter

Simon, Vivien Klaudia

Institute/workplace of the presenter

Department of Biophysics and Radiation Biology, Semmelweis University

Authors

Vivien Klaudia Simon¹
1: Department of Biophysics and Radiation Biology, Semmelweis University

Text of the abstract

Microgravity has been shown to significantly alter bacterial physiology, including antibiotic susceptibility and host-pathogen interactions. These changes may lead to increased bacterial resistance, posing a risk to astronaut health during long-duration space missions. A promising alternative antimicrobial strategy is phage therapy, which uses bacteriophages to selectively target bacteria. Previous studies of the Escherichia coli-T7 phage system have reported altered infection dynamics in space, including delayed infection onset followed by the emergence of resistant bacterial populations.
In this study, we aim to investigate the mechanisms underlying these changes, with a particular focus on early host-phage interaction dynamics using a ground-based simulated microgravity model.
Microgravity conditions were simulated by a custom-designed 2D clinostat at 15-90 RPM. Samples of E. coli and E. coli+T7 phage were prepared using defined bacteria-to-phage ratios and incubated at 37°C under clinorotation (0G) and static control (1G) conditions. Bacterial growth and infection dynamics were monitored via optical density measurements at 600 nm wavelength (OD600) until saturation was reached (140 min). Following chemical fixation, samples were analyzed using optical microscopy and atomic force microscopy (AFM).
Simulated microgravity (0G) significantly altered E. coli growth dynamics, with a maximum reduction of 93% in OD600 observed from 100 minutes (p < 0.05), which was not present in 1G controls. This effect seemed to increase with higher rotational speeds. Phase contrast microscopy revealed E. coli aggregates up to 100 µm under 0G, with no significant change in cell size. Similar OD trends were observed in E. coli-T7 co-cultures, without measurable effects on infection kinetics.
Simulated microgravity induced E. coli aggregation, consistent with membrane alterations that may modulate susceptibility to T7 infection. However, no significant effect on infection kinetics was observed within the studied timeframe. Ongoing AFM analyses will study microgravity-induced changes in spatial organization and phage docking dynamics at molecular level, while future studies will incorporate extended incubation periods to capture longer-term effects.
This research was funded by the University Research Scholarship Programme (EKÖP) of the Ministry of Culture and Innovation.