title: Exocellular and intracellular accumulation of lead in Pseudomonas fluorescens ATCC 13525 is mediated by the phosphate content of the growth medium.
abstract: Pseudomonas fluorescens appears to elicit disparate lead detoxification mechanisms in phosphate-rich and phosphate-deficient media. When grown in the presence of 0.1 mM Pb2+ complexed to citrate, the sole source of carbon, only a slight diminution in cellular yield was observed in the former medium. However, in a phosphate-deficient milieu, lead imposed approximately a 30% reduction in bacterial multiplication. At stationary phase of growth, 72% of the metal was found in the bacterial cells from the phosphate-deficient medium, while that from phosphate-rich broth contained only 12.5%. The latter medium was characterized by an insoluble pellet that accounted for 73.5% of the lead. Although no citrate was detected in the phosphate-rich media after 40 h of incubation, only 72% of citrate was consumed even after 70 h of growth in the phosphate-deficient cultures. The inclusion of lead did not appear to enhance the production of either extracellular proteins or carbohydrates.
authors.affiliation: Department of Chemistry and Biochemistry, Laurentian University, Sudbury, Ontario, Canada.
authors.forename: A
authors.initials: A
authors.lastname: al-Aoukaty
authors.forename: V D
authors.initials: VD
authors.lastname: Appanna
authors.forename: J
authors.initials: J
authors.lastname: Huang
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis; D050260:Carbohydrate Metabolism; D002951:Citrates / Q000378:metabolism; D003470:Culture Media; D007700:Kinetics; D007854:Lead / Q000378:metabolism* / Q000494:pharmacology; D010710:Phosphates / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D013050:Spectrometry, Fluorescence
chemical_list: D001426:Bacterial Proteins; D002951:Citrates; D003470:Culture Media; D010710:Phosphates; D007854:Lead