Effect of different environmental parameters on the biofilm build-up of Pseudomonas putida ATCC 11172 in chemostat

Summary

The influence of carbon source, cell concentration, oxygen tension, pH and temperature on the biofilm build-up of Pseudomonas putida ATCC 11172 was studied. The experiments were performed in a carbon and energy limited chemostat (asparagine). When the asparagine was replaced by glucose the biofilm build-up was decreasing.

Cell concentration, oxygen tension or temperature did not to any significant degree affect the biofilm build-up. Temperature, however influenced the size of the suspended cells. The cell size successively increased with decreasing temperature. A similar change in cell size could be accomplished by increasing the dilution rate from 0.2 h⁻¹ (small cells) to 0.7 h⁻¹ (large cells).

The biofilm build-up increased with increasing pH in the interval of 5.5–6.7. The viable count of the biofilm after 24 h exposure of test surface increased from 8×10⁶ cfu/cm² to 1.6×10⁸ cfu/cm² while the biomass increased by a factor of about 70.