“…To optimize the removal, it is important to evaluate the behavior of heavy metals together with the characteristics of the adsorbent; in the literature, it has been found that the mechanism of biosorption is not yet fully understood as this process is determined by physiology, chemical and physicochemical factors, ionic strength, i.e., metal ion chemistry, pH, temperature, metal concentration, contact time, the composition of the cell wall, and physiological characteristics of the microorganism [41][42][43]. Although the removal of Pb was not considerable or close to the permitted levels (0.05 mg/L) according to Peruvian legislation, possibly due to extrinsic and intrinsic aspects of the bacterium or due to independent variables that were not taken into account, for example, the contact time, this study serves as a reference to establish differences regarding the methods of removal of Pb by the bacterium S. marcescens [44,45].…”