Effect of Cadmium on the Morphology, Membrane Integrity and Permeability of Pseudomonas putida

• Published in: Journal of general microbiology Vol. 132; no. 6; pp. 1475 - 1482
• Main Authors: Higham, Denise P, Sadler, Peter J, Scawen, Michael D
• Format: Journal Article
• Language: English
• Published: London Soc General Microbiol 01-06-1986; New York, NY Cambridge University Press
• Subjects: Action of physical and chemical agents on bacteria; Bacteriology; Biological and medical sciences; cadmium; Fundamental and applied biological sciences. Psychology; membrane permeability; membrane structure; Microbiology; Pseudomonas putida; Pseudomonadales; Culture medium; Cadmium; Permeability; Electron microscopy; Antibiotic; Morphology; Microorganism culture; Lipopolysaccharide; Bacteria; Pseudomonadaceae; Membrane; Pseudomonas putida
• ISSN: 0022-1287; 1350-0872; 1465-2080
• DOI: 10.1099/00221287-132-6-1475

1 Department of Chemistry, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK
2 Microbial Technology Laboratory, Centre for Applied Microbiology and Research, Porton Down, Salisbury SP4 0G9, UK
ABSTRACT
Summary: Cadmium-adapted Pseudomonas putida exhibited a long lag phase (6 h) on incubation in a defined medium containing 3 mM-Cd 2+ . During this time extensive blebbing of the outer membrane was observed by electron microscopy and polyphosphate granules containing Cd 2+ were present in the cells. Cells from exponential-phase cultures of cadmium-adapted P. putida were found in clusters. They were much smaller than control cells grown without cadmium, and contained electron-dense aggregates. Cadmium-adapted cells released more lipopolysaccharide and protein into the external medium than did control cells; the addition of Ca 2+ , but not Mg 2+ , to the medium prevented this increased release. Cadmium-adapted cells also showed greatly increased sensitivity towards certain antibiotics, including the aminoglycosides, cyclic polypeptides and doxycycline. It is suggested that this is related to changes in membrane structure.