Application of Yeasts as Pollutant Adsorbents

Pollutants are chemicals introduced into the environment that produce deleterious impacts on human health and ecosystems, causing disease, global warming, and increased mortality. Bioremediation through microbial biomass is a low-cost and eco-friendly approach to the removal of pollutants. Yeasts, however, have been found to have high capacity to adsorb and detoxify several contaminants under nonsterile and low-cost conditions.This paper discusses the use of yeasts in bioremediation through the adsorption of pollutants such as heavy metals, mycotoxins, dyes, heterocyclic aromatic compounds, pesticides, and off-flavors. Understanding the cell wall composition of the yeast is necessary to comprehend the process of biosorption, in which it occurs through physical adsorption, precipitation, complexation, ion exchange, and redox reactions. The kinetics of biosorption and the factors controlling its effectiveness are also discussed.Besides adsorption, yeasts employ enzymatic degradation by cytochrome P450 monooxygenases, laccases, and glutathione S-transferases, as well as intracellular sequestration via metal-binding peptides and vacuolar compartmentalization. Such mechanisms aid in detoxification and pollutant removal. Food wastewater and decontamination uses of food strengthen the diversity and industrial potential of yeasts. This review synthesizes current knowledge on yeast-mediated pollutant removal, providing recommendations for the optimization of bioremediation methods in environmental and industrial use.