ISSN:
1476-5535
Keywords:
Keywords: nickel; heavy metals; biosorption; pH; accumulation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Accumulation of heavy metals by Pseudomonas fluorescens 4F39 was rapid and pH-dependent. The affinity series for bacterial accumulation of metal cations decreased in the order Ni〉〉Hg〉U〉〉As〉Cu〉Cd〉Co〉Cr〉Pb. Metal cations were grouped into those whose accumulation increased as the pH increased, with a maximum accumulation at the pH before precipitation (Ni, Cu, Pb, Cd, Co), and those whose maximum accumulation was not associated with precipitation (Cr, As, U, Hg). High Ni2+ accumulation was studied. Electron microscopy indicated that at pH 9, Ni2+ accumulated on the cell surface as needle and hexagon-like precipitates, whose crystalline structure was confirmed by electron diffraction analysis and corresponded to two different orientations of the nickel hydroxide crystals. Crystals on cells showed marked anisotropy by X-ray powder diffraction, which differentiated them from crystals observed in nickel solution at pH 10 and 11 and from commercial nickel hydroxide. Nickel biosorption by Pseudomonas fluorescens 4F39 was a microprecipitation consequence of an ion exchange. Journal of Industrial Microbiology & Biotechnology (2000) 24, 146–151.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1038/sj.jim.2900793
