Lactobacillus fermentum and Lactobacillus plantarum bioremediation ability assessment for copper and zinc.

Some probiotic strains, such as Lactobacillus spp., are options for the removal of heavy metals from food, water and soil. Although copper or zinc are essential for use in many biochemical processes, they are toxic at high concentrations. The purpose of the current study was to evaluate two Lactobacillus strains for their application in the bioremediation of copper and zinc from aqueous solution. The biomass of Lactobacillus fermentum and Lactobacillus plantarum were treated with different concentrations of copper or zinc (0-200 mM). Minimum inhibitory concentration, biosorption capacity and kinetic biosorption behavior were determined. The results showed rapid biosorption of both metals and both species, removed zinc ions more efficient than copper. The highest removal rate of zinc reached 84% for the L.fermentum. Moreover, Freundlich and Langmuir model indicated that L.fermentum showed a higher capability to biosorp heavy metal compared to L.plantarum. It was concluded that L.fermentum biomass, a widely available and highly efficient biosorbant, could be applied for zinc or copper bioremediation from the aquatic environment.