Screening of lactic acid bacteria to detect potent biosorbents of lead and cadmium

Abstract

In this study, the ability of 19 strains of local Lactic acid bacteria in reducing Cd (II) and Pb (II) has been evaluated, in vitro. The average uptake of metal ions was determined per cell and the effect of dead and live cells, metal concentration, pH and contact time were analyzed for the selected LAB with highest heavy metal biosorption. All tested Lactobacillus strains adsorbed cadmium and lead, and among them Lactobacillus plantarum subsp. plantarum PTCC 1896 showed the highest uptake in a fast and pH-dependent process. The qmax for Cd (II) and Pb (II) removal by L. plantarum PTCC 1896 using a Langmuir isotherm were 122.7 ± 37.3 mg/L and 34.5 ± 2.9 mg/L, respectively. Conclusively, both live and dead cells of L. plantarum PTCC 1896 are efficient cadmium and lead biosorbent to decrease heavy metal contamination in aqueous media.