P Sar1, S K Kazy, S P Singh. 1. Department of Botany, Banaras Hindu University, Varanasi, India. sarpinaki@yahoo.com
Abstract
AIMS: To investigate intracellular localization of nickel and its chemical nature in Pseudomonas aeruginosa. METHODS AND RESULTS: Transmission electron micrographs of Ni-loaded bacteria exhibited a darkened electron opaque zone throughout the cell periphery. Energy dispersive X-ray analysis confirmed the deposition of metallic nickel. Cell fractionation revealed that 88% of the accumulated nickel was restricted to the periplasm and membrane. X-ray diffraction patterns ascertained the chemical nature of cellular Ni as phosphide (Ni5P4, NiP2 and Ni12P5) and carbide (Ni3C) crystals. CONCLUSION: Pseudomonas aeruginosa accumulated nickel as its phosphide and carbide crystal mostly in the cell envelope region, indicating the predominant role of phosphoryl and carboxyl/carbonyl groups of cell wall/membrane components in cation sequestration. SIGNIFICANCE AND IMPACT OF THE STUDY: The data contribute significantly to a better understanding of bacteria-metal interaction and will be useful in developing biotechnological strategies for toxic metal bioremediation.
AIMS: To investigate intracellular localization of nickel and its chemical nature in Pseudomonas aeruginosa. METHODS AND RESULTS: Transmission electron micrographs of Ni-loaded bacteria exhibited a darkened electron opaque zone throughout the cell periphery. Energy dispersive X-ray analysis confirmed the deposition of metallic nickel. Cell fractionation revealed that 88% of the accumulated nickel was restricted to the periplasm and membrane. X-ray diffraction patterns ascertained the chemical nature of cellular Ni as phosphide (Ni5P4, NiP2 and Ni12P5) and carbide (Ni3C) crystals. CONCLUSION:Pseudomonas aeruginosa accumulated nickel as its phosphide and carbide crystal mostly in the cell envelope region, indicating the predominant role of phosphoryl and carboxyl/carbonyl groups of cell wall/membrane components in cation sequestration. SIGNIFICANCE AND IMPACT OF THE STUDY: The data contribute significantly to a better understanding of bacteria-metal interaction and will be useful in developing biotechnological strategies for toxic metal bioremediation.
Authors: Evgenya S Shelobolina; Maddalena V Coppi; Anton A Korenevsky; Laurie N DiDonato; Sara A Sullivan; Hiromi Konishi; Huifang Xu; Ching Leang; Jessica E Butler; Byoung-Chan Kim; Derek R Lovley Journal: BMC Microbiol Date: 2007-03-08 Impact factor: 3.605