Microbes in Heavy Metal Remediation: A Review on Current Trends and Patents

Abstract

This review paper will focus on the microbial bioremediation process and highlight some of the newly developed patented methods for microbial bioremediation of the heavy metals from the environmental samples using microbial populations.

Recent Progress in Metal-Microbe Interactions: Prospects in Bioremediation

“…Biomass has been shown to be as efficient as many ion exchange resins for this type of removal. The process can be employed to concentrate and recovering metals, primarily from water solutions 69,70,71,72 . Selected microorganisms through oxidation or reduction of metals remediate various types of metal contaminates in surrounding environment.…”

“…Selected microorganisms through oxidation or reduction of metals remediate various types of metal contaminates in surrounding environment. The redox reactions can accomplished directly by the organism or may be as a consequence of a reducing agents released by them 69,70,71,72 . Biological methylation refers to the process in which organisms attach a methyl group (-CH 3 ) to an inorganic form of metal.…”

“…Methylation directly affects the mobility of the metal. Among metals known to be methylated or demethylated by microorganisms are mercury, arsenic, cadmium, and lead 69,70,71,72 . Biosorption refers to the process of being taken up or hold by either adsorption or absorption of a molecule by an organism.…”

Treatment of chromium contaminated soil by co-pyrolysis with rice straw

“…Unlike organic contaminants, chromium in the soil environment can not be destroyed by chemical degradation or biodegradation, but remain in soils causing biomagnifications. They would also accumulate in the food chain, which contributes to a significant threat to public health and safety (Mishra, 2017). Recently, Cr contamination in soil was frequently reported in the world (Ballesteros et al, 2017;Khan, 2001), and Cr discharges into the environment were found to far exceed the international guidelines values (50-100 kg per year) (Gil-Cardeza et al, 2014).…”

“…Cr as one of the hazardous heavy metals cannot be destroyed by chemical degradation or biodegradation, but remains and accumulates in the soil leading to biomagnifications (Mishra, 2017). However, Cr contaminants are still largely generated and increase in total amount due to rapid and continuing economic development (Liikanen et al, 2018).…”