Lead bioremoval from milk by Saccharomyces cerevisiae

Abstract

The present study refers to the application of Saccharomyces cerevisiae for bioremoval of lead from milk, the most important dairy product. First, the impact of process variables on lead bioremoval by S. cerevisiae has been studied by Plackett-Burman Design. Then, the optimization of bioremoval process was carried out by three main factors; contact time, biomass and initial heavy metal concentration by using a central composite design. The analysis of variance showed that the models were highly significant. The model also described that lead bioremoval from milk is affected by all three factors. The optimized bioremoval was achieved after 4 days with 22 × 108 CFU inoculation of yeast in milk containing 70 μg/l of lead concentration. The reconfirmation test indicated that in the above mentioned optimum condition the highest yield of lead bioremoval was achieved at 70%. 3D plots analysis represented dual interaction effects on metal bioremoval. This study showed that S. cerevisiae is a natural potential biosorbent for lead bioremoval from milk. This approach could be also considered as a green technology useful in eliminating the heavy metal contaminations of drinking water and foodstuff.