Impact of Nutrient Starvation on Biofilm Formation in Pseudomonas aeruginosa: An Analysis of Growth, Adhesion, and Spatial Distribution

<b>Objectives:</b> This study investigates the impact of nutrient availability on the growth, adhesion, and biofilm formation of <i>Pseudomonas aeruginosa</i> ATCC 27853 under static conditions. <b>Methods:</b> Bacterial behaviour was evaluated in nutrient-rich Luria-Bertani (LB) broth and nutrient-limited M9 media, specifically lacking carbon (M9-C), nitrogen (M9-N), or phosphorus (M9-P). Bacterial adhesion was analysed microscopically during the transition from reversible to irreversible attachment (up to 120 min) and during biofilm production/maturation stages (up to 72 h). <b>Results:</b> Results demonstrated that LB and M9 media supported bacterial growth, whereas nutrient-starved conditions halted growth, with M9-C and M9-N inducing stationary phases and M9-P leading to cell death. Fractal analysis was employed to characterise the spatial distribution and complexity of bacterial adhesion patterns, revealing that nutrient-limited conditions affected both adhesion density and biofilm architecture, particularly in M9-C. In addition, live/dead staining confirmed a higher proportion of dead cells in M9-P over time (at 48 and 72 h). <b>Conclusions</b>: This study highlights how nutrient starvation influences biofilm formation and bacterial dispersion, offering insights into the survival strategies of <i>P. aeruginosa</i> in resource-limited environments. These findings should contribute to a better understanding of biofilm dynamics, with implications for managing biofilm-related infections and industrial biofouling.