Spectroscopic characterization on the biosorption and bioreduction of Ag(I) by Lactobacillus sp. A09

Some characteristics of Ag+ biosorption and bioreduction by Lactobacillus sp. A09 biomass were reported. The optimum pH value of Ag+ biosorption by strain A09 was 4.5. Temperature(6 similar to 50 degrees C) did not affect the biosorption. The biosorptive efficiency (91%) and biosorptive capacity(Ag(+)125 mg . g(-1) dry weight biomass) were achieved under the conditions of Ag(+)100 mg . L-1, biomass 800 mg . L-1, pH 4.5 and 30 degrees C for 24 h contact, TEM analysis indicated that A09 biomass could reduce Ag+ to Ag-o as Ag particles on the surface of cells. IR spectroscopy showed that -CO2- and -HN -C = O on the surface of cells may involve in the precession for adsorbing Ag+.