Lead removal at trace concentrations from water by inactive yeast cells

Abstract

Traces of heavy metals found in water resources, due to mining activities and e-waste discharge, pose a global threat. Conventional treatment processes fail to remove toxic heavy metals, such as lead, from drinking water in a resource-efficient manner when their initial concentrations are low. Here, we show that by using the yeast Saccharomyces cerevisiae we can effectively remove trace lead from water via a rapid mass transfer process, called biosorption, achieving an uptake of up to 12 mg lead per gram of biomass in solutions with initial lead concentrations below 1 part per million. Through spectroscopic analyses, we found that the yeast cell wall plays a crucial role in this process, with its mannoproteins and β-glucans being the key potential lead adsorbents. Furthermore, by employing nanomechanical characterization in the yeast biomass, we discovered that biosorption is linked to an increase in cell wall stiffness. These findings open new opportunities for using environmentally friendly and abundant biomaterials for advanced water treatment targeting emerging contaminants.

Spent brewer’s yeast as a selective biosorbent for metal recovery from polymetallic waste streams

“…Based on this, at pH values below 4.0, protonation of the functional groups on the yeast surface is expected whereas at higher pH values the yeast surface may have an overall negative charge. This could be beneficial for attracting positively charged metal ions, if the biosorption is mainly driven by electrostatic interactions ( Stathatou et al, 2022 ; Zinicovscaia et al, 2023 ). According to the results of the DoE experiments, pH 3.5 for Al 3+ , 5.0 for Cu 2+ , 7.5 for Zn 2+ and 8.5 for Ni 2+ have been proven to be most suitable for removal of the respective metal ion out of single-metal solutions within these experimental conditions.…”

Simultaneous Removal of Metal Ions from Wastewater by a Greener Approach

“…These deformations of peaks presented in the FTIR spectrum can be surveyed as evidence of biosorption. In addition, no new absorption bands were found to be pertinent for showing that the biosorption of investigated metal ions is not involved in the formation of covalent bonds and that it is performed predominantly through ion-exchange interactions (that are electrostatic) [48,[65][66][67].…”

“…When compared to the original sample, the peak 1239 cm −1 had not changed, indicating that the lead atoms did not bind to the phosphate group. However, some peaks had a slight shift to a lower wavelength (3413-3407, 2928-2926, 1644-1641, 1550-1543, 1380-1373, 1072-1062, and 537-535 cm −1 ), suggesting the intervention of hydroxyl, methyl, acetyl, carboxyl, sulfide, Pb-O, and ring deformation groups during Pb(II) adsorption [48,65].…”

“…The prepared yeast has a higher surface area than is found in the literature [24,54], which confirms the higher result of q max than is found in the literature. is not involved in the formation of covalent bonds and that it is performed predominantly through ion-exchange interactions (that are electrostatic) [48,[65][66][67].…”

Yeast-laden hydrogel capsules for scalable trace lead removal from water

“…20 Biosorption, a mass transfer process by which an ion or molecule binds onto inactive biological materials by physicochemical interactions, 21 can offer a sustainable and effective alternative to conventional processes. As shown previously, 1 trace lead can be effectively removed from water by using the yeast Saccharomyces cerevisiae (S. cerevisiae). Yeast rapidly treats water with environmentally relevant initial lead concentrations below 1 part per million (ppm), attaining equilibrium within the rst 5 min of contact.…”