Decolorization of the anthraquinone dye Cibacron Blue 3G-A with immobilized Coprinus cinereus in fluidized bed bioreactor.

Coprinus cinereus, which was able to decolorize the anthraquinone dye Cibacron Blue 3G-A (CB) enzymatically, was used as a biocatalyst for the decolorization of synthetic solutions containing this reactive dye. Coprinus cinereus was immobilized in both calcium alginate and polyacrylamide gels, and was used for the decolorization of CB from synthetic water by using a fluidized bed bioreactor. The highest specific decolorization rate was obtained when Coprinus cinereus was entrapped in calcium alginate beads, and was of about 3.84 mg g(-1) h(-1) with a 50% conversion time (t1/2) of about 2.60 h. Moreover, immobilized fungal biomass in calcium alginate continuously decolorized CB even after 7 repeated experiments without significant loss of activity, while polyacrylamide-immobilized fungal biomass retained only 67% of its original activity. The effects of some physicochemical parameters such as temperature, pH and dye concentration on decolorization performance of isolated fungal strain were also investigated.

Volatilization of mercury by immobilized bacteria (Klebsiella pneumoniae) in different support by using fluidized bed bioreactor.

Klebsiella pneumoniae, a mercury-resistant bacterial strain able to reduce ionic mercury to metallic mercury, was isolated from wastewater of Casablanca. This strain exhibits high minimal inhibition concentrations for heavy metals such as mercury 2400 microM, lead 8000 microM, silver 2400 microM, and cadmium 1000 microM. This bacterium was immobilized in alginate, polyacrylamide, vermiculite, and cooper beech and was used for removing mercury from a synthetic water polluted by mercury by using a fluidized bead bioreactor. Immobilized bacterial cells of Klebsiella pneumoniae could effectively volatilize mercury and detoxify mercury compounds. Moreover, the efficiency of mercury volatilization was much greater than with the native cells. The highest cleanup and volatilization rates were obtained when Klebsiella pneumoniae was entrapped in alginate beads, with a cleanup rate of 100% and a volatilization rate of 89%. Immobilized cells in alginate continuously volatilized mercury even after 10 days without loss of activity.

Complexation and ionophoric properties of taxol and colchicine: complex formation and transport of sodium, potassium, magnesium and calcium ions across a liquid membrane.

We report the activities of taxol (an anticancer drug) and colchicine, which are inhibitors of microtubule organization, on the complexation and transport of Na+, K+, Mg2+ and Ca2+ ions across a liquid membrane, using a spectrophotometric procedure. Taxol, a diterpenoid compound, that has been demonstrated to possess a potent antitumour activity, is shown to extract Na+, K+, Mg2+ and Ca2+ ions from the aqueous solution to the organic phase with preference for Ca2+ ions. A kinetic study of the transport and complexation of Na+, K+, Mg2+ and Ca2+ ions through a liquid membrane revealed that the K+ ion is more rapidly transported and the Ca2+ ion is more rapidly complexed than other ions. However, colchicine, another alkaloid compound, extracted and transported only the divalent ions tested, Mg2+ and Ca2+. In both complexation and transport, the flux of the ions increases with the concentration of taxol or colchicine. Complexation and ionophoric properties of taxol and colchicine sheds new lights on therapeutic properties of these drugs. The treatment of disease states by the administration of these drugs to alter membrane permeability will prove to be a valuable therapeutic concept.