8. Microbial Remediation of Mercury: An Overview

Mercury (Hg) jeopardizes ecological balance and public health globally owing to its cytotoxicity, indegradability, coexistence in different chemical forms, uneven distribution, mobility, and long-lasting in the atmosphere. Therefore, the endeavors for feasible, economic, systematic, easily available, and sustainable approaches can be customized, which are conclusively enduring. Bioremediation, particularly microbial remediation means, as a greener and cheaper strategy has piqued the interest of biotechnologists and ecologists to mitigate Hg risk. By the virtue of versatile physiological performance, microorganism either prokaryotic or eukaryotic in planktonic or in the sessile-biofilm state, solitary or in consortium, indigenously occurred or intendedly introduced as GMO under aerobic or anaerobic circumstances and even extremophiles, have the ability to detoxify Hg and transform its phase to less-toxic valence through various metabolic scenarios like biosorption, bioprecipitation, bioleaching, bioaccumulation, and biovolatilization. Importantly, all previous mechanisms were catalyzed by different enzymatic systems including mercuric reductase and organomercurial lyase. However, their recruitment in in situ or ex situ technologies also implemented sensibly. Interestingly, the combined remediation technology boosted microbial-remediating efficiency and potentiality, especially upon hybridizing microbes with novel biosorbents such as carbon-based material, polymer, and nanoparticles. All preceding aspects were addressed in detail inclusively in this chapter to compensate the gap among knowledge, lab-scale practice, and field-scale application for alleviating Hg-toxicity.