RESUMO
The microorganisms used for the mercury retention experiments were natural isolates and genetically engineered bacteria. All mercury-resistant strains contained the merA gene. Column experiments with these strains were carried out by immobilizing them on different support materials. To obtain kinetic data of the reductase activity for whole cells and the crude extract, batch experiments were carried out under different conditions.
Assuntos
Aeromonas/genética , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Mercúrio/isolamento & purificação , Pseudomonas putida/genética , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/isolamento & purificação , Elementos de DNA Transponíveis , Mercúrio/farmacologia , Mutagênese Insercional , Óperon , Regiões Promotoras Genéticas , Mapeamento por Restrição , Saccharomyces cerevisiae/genéticaRESUMO
The osmotic coefficients phi p,Na of dilute solutions of the sodium form of some weakly acidic polymers are theoretically predicted in this work. Based on the measured value 0.73 of gamma Na, the activity coefficient of free Na+, of the completely ionized humic acid (sodium salt) in a salt-free solution, the effective interligand distance b is calculated to be 11.34 A by using Manning's counterion condensation theory [Manning, G. S. (1969) J. Chem. Phys. 51(3), 924]. The corresponding values of gamma Na (measured experimentally) and b for the completely ionized exopolymer of Pseudomonas atlantica are 0.624 and 7.57 A when cultivated at a dilution rate D = 0.015 h-1, 0.647 and 8.19 A at D = 0.025 h-1, and 0.613 and 7.29 Aat D = 0.06 h-1. For alginic acid (in the completely ionized sodium form), gamma Na = 0.40 and b = 4.71 A. The osmotic coefficients phi p,Na for the partially and the completely ionized polymers are then predicted with Manning's theory as well.
