Heavy metal remediation and resistance mechanism of Aeromonas, Bacillus, and Pseudomonas: A review

Heavy metals entered in the soil from numerous sources and reduce the crop growth, productivity, and the quality of the soil environment. Uptake of heavy metals by plants and microorganisms is synchronized through the influences of many factors, such as complex soil-plant and microorganism processes. Soil microorganisms are closely associated with soil fertility and are considered important indicators of healthy soils. Various microorganisms have different strategies and mechanisms for survival in heavy metal-contaminated environments such as biosorption, and secretion of compounds that form complexes with heavy metals. The present paper reviewed the recent literature pertaining to heavy metal uptake and tolerance mechanisms of the most important microbial genera viz Aeromonas, Bacillus, and Pseudomonas. This review also focused on the survival and adaptations of selected microbial genera in heavy metal polluted soil habitats which may be helpful in maintaining healthy conditions of agricultural soils. Overall, this review provided the comprehensive knowledge pertaining to heavy metals, their effects on living organisms, and the metal uptake and resistance mechanisms of the selected bacterial genera.