Applications of Yeasts in Heavy Metal Remediation
Qi Shao, Shihui Yan, Xin Sun, Hongming Chen, Yunzhuo Lu, Siqi Li, Yunjie Huang, Shimei Wang, Min Zhang, Zhen Li
Abstract
Yeasts have been extensively recognized as a type of model microorganism due to their facile cultivation, short growth cycle, and genetic stability. Different yeast strains, such as Saccharomyces cerevisiae and Rhodotorula mucilaginosa, have exhibited notable sorption capacities for heavy metals and metalloids. Yeast employs diverse pathways for detoxifying heavy metals via its cell walls, intracellular organelles, and extracellular polymeric substances (EPSs). The cell wall has many functional groups to adsorb metals, decreasing their concentrations in the environment. In intracellular regions, some proteins are capable of transporting metals into biological metabolic processes for detoxification. In extracellular regions, electrostatic as well as complexation mechanisms between protein in EPSs and heavy metals is well accepted. Meanwhile, mannose and glucose within EPSs are target sugars for complexation with metals. Many yeasts can hence work as excellent biomaterials for the bioremediation of metal pollution. Meanwhile, they can be combined with other materials to enhance remediation efficiency. This study reviews underlying mechanisms and cases of yeast-mediated metal detoxification, alongside highlighting yeasts’ industrial applications as bioremediation materials.