ISSN:
1573-0972
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract A strain of broad-spectrum, mercury-resistant Pseudomonas putida FB1 was used to remove mercury as the gaseous element (Hg(0)) from a continuous axenic culture, fed with a synthetic medium containing 1 mg Hg l-1 as HgCl2. Mercury determinations were performed in steady-state cultures using various culture fractions [whole culture, filtered supernatant, bacterial cells (dry wt), recovery trap liquid] in order to determine the removal efficiency at different dilution rates (from 0.1 to 3.0 day-1). The removal efficiency ranged from 99.2% to 99.8%, and the residual Hg was maintained below 5 μ l-1 (the maximum allowable concentration of Hg in liquid wastes according to Italian law) at a dilution rate of 1.0 day-1, corresponding to a Hg flux of 40 μg l-1 h-1. Hg accumulation by cell biomass was negligible for dilution rates under 1.0 day-1. A progressive accumulation of Hg, both in the liquid phase and in cells, occurred at a higher dilution rate (3.0 day-1; close to washout), corresponding to a Hg concentration of 25 μg g-1 (dry wt). The estimated Km and Vmax for Hg reduction were 0.241 mg l-1 and 9.5 mg g-1 h-1, respectively. In batch experiments maximum Hg removal occurred at the optimum growth temperature (28°C) of P. putida. The maximum recovery of Hg in the liquid trap was 78%.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00327854
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