Transport and accumulation of nickel ions in the cyanobacterium Anabaena cylindrica.

摘要: The uptake of nickel ions by the cyanobacterium Anabaena cylindrica was studied. Nickel transport dependent on membrane potential cells and rate decreased in dark or addition inhibitors, including uncouplers electron which abolished cells. process obeyed hyperbolic kinetics, with a high affinity (apparent Km = 17 ± 11 (SEM) nM) low turnover number (maximum velocity 22.3 5.4 pmol h−1 mg dry wt−1 flux 3.1 nmol m−2 plasma surface area). also apparently specific for Ni2+, being unaffected presence range other metal large excess. Equilibrium experiments showed that, over ion concentrations, concentrated Ni2+ factor 2700 240 (SEM)-fold, corresponding to chemical diffusion 101 mV. It concluded that carrier-facilitated concentration determined cell according Nernst equation.