response surface design for removal of lead by different lactic acid bacteria

Background: toxic heavy metals, such as lead, are widely used in industry and may cause serious health problems and ecological hazards for living organisms. objectives: the current study aimed to investigate the removal efficiency of lead by lactobacillus strains using a methodological approach. methods: after selecting the bacteria with the maximum metals removal ability, experiments were conducted according to (i) the plackett-burman design (minitab18 program) to screen several significant process factors and (ii) central composite design (design-expert 11.1.2.0 program) to find out the optimum process conditions for the maximum capacity of metal removal efficiency. results: the optimum ph, metal, and bacterial concentration were 6.76, 391 mg.l^-1, and 4.60 g.l^-1 for lead removal ability of l. acidophilus atcc4356. a quadratic model was developed to correlate the variables with removal efficiency. according to the results, this model was not statistically significant (p > 0.05). conclusions: the experimental removal efficiencies at the optimum condition for lead by l. acidophilus atcc4356 (73.9%) were consistent with the predicted values. consequently, due to their appreciate efficiency and the lower cost of the lead removal ability, these two bacteria may be a candidate as good biosorbents. the results also confirmed that the response surface methodology is an appropriate methodology for modeling of removal efficiency.