Interaction of metals and protons with anoxygenic phototrophic bacteria Rhodobacter blasticus

摘要: Abstract Towards a better understanding of acid–base properties and metal adsorption capacities the first primary producers on Earth, surface chemistry non-sulfur anoxygenic phototrophic bacteria (APB) Rhodobacter blasticus f-7 was characterized using combination potentiometric titration methods electrophoretic mobility measurements as function pH (3 to 11) ionic strength (0.001 1.0 M). Surface titrations were performed limited residence time reactors taking into account cell-wall bound Ca Mg from culture media for net proton balance calculations. Electrophoretic mobilities live APB cells investigated in 0.001–0.5 M NaCl at 1 11 different Zn, Cd Pb concentrations. Adsorption Cd, Pb, Cu, Co, Ni, Sr, Al, Ga, Ge, Mo, W studied 25 °C 0.01 M NaNO3 concentration batch reactors. A competitive Langmuir sorption isotherm conjunction with linear programming optimization method (LPM) used fit experimental data assess number nature (carboxylate, phosphoryl/phosphodiester amine) sites reaction constants involved binding trace metals surface. We found that total H/OH site (60–120 μmol/gwet) is comparable cyanobacteria previously by same technique (50–200 μmol/gwet). Similarly, LPM parameters are close agreement those observed cyanobacteria. As such, results present study indicate similar affinity both surfaces divalent micronutrients, most likely due dominance carboxylate phosphorylate rather high loading.