Pseudomonas aeruginosa under Phosphorus-Poor Culture Conditions: Phospholipid-Poor Bacterial Membranes, and Susceptibility to Antibacterial Chemicals, High Temperature and Low pH

Abstract

Pseudomonas aeruginosa, Pseudomonas fluorescens, and Burkholderia cepacia were able to grow in a phosphorus-poor (0.01 mM of phosphate) synthetic medium in chemostat cultures. In contrast to bacteria grown in a phosphorus-rich (10 mM of phosphate) chemostat, they underwent an extensive changes in lipid composition, with phospholipids being replaced with ornithine-containing lipids. Nevertheless, their susceptibility to twelve antibiotics, and seven germicides changed little. No special tendencies in drug susceptibility related to the replacement of membrane lipids were recognized. Thus, though growing in a phosphorus-poor environment, these bacteria did not exhibit any special resistance to antibacterial agents. With regard to susceptibility to low pH, P. aeruginosa grown under phosphorus-poor conditions demonstrated greater resistance.