Biofilm and metallothioneins: A dual approach to bioremediate the heavy metal menace

Abstract

AbstractMetallothioneins are a class of proteins produced by both prokaryotes and eukaryotes, having low molecular weight and abundant cysteine residues. These proteins play a humongous role in binding, sequestration, and even buffering of the intracellular metal ions. Though they are a wide class of proteins, much of them are yet to be explored. Their metal binding attribute is unique and they form distinctive metal‐thiolate clusters. They have also been known to have ROS scavenging activities due to the presence of the cysteine residues. Phytochelatins also play major roles in metal sequestration pathways. Biofilms on the other hand are clusters of bacterial cells surrounded by an extracellular matrix of polymeric substances secreted by the bacteria themselves. Biofilms play multiple roles, from nutrient sequestration, stress resistance to surface adherence. But lesser explored arenas include assistance in heavy metal trapping and bio‐remediation. Researchers have conducted studies that have demonstrated increased metal trapping, resistance and uptake in biofilm forming strains than non‐biofilm forming mutants. Therefore, this study would explore the dual role of metallothionein and biofilm in their activity of metal sequestration and heavy metal remediation and provide certain insights so as to keenly understand the correlations between the two.