Intracellular nickel accumulation by Pseudomonas aeruginosa and its chemical nature.
OBJECTIVE
To investigate intracellular localization of nickel and its chemical nature in Pseudomonas aeruginosa.


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.


CONCLUSIONS
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.


CONCLUSIONS
The data contribute significantly to a better understanding of bacteria-metal interaction and will be useful in developing biotechnological strategies for toxic metal bioremediation.
Sar
P
P
Department of Botany, Banaras Hindu University, Varanasi, India. sarpinaki@yahoo.com
Kazy
S K
SK
Singh
S P
SP
D001673:Biodegradation, Environmental; D002462:Cell Membrane; D002473:Cell Wall; D055598:Chemical Phenomena; D002621:Chemistry; D009532:Nickel / Q000737:chemistry / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000378:metabolism* / Q000648:ultrastructure
D009532:Nickel