Engineered and Nanostructured Bacteria for Heavy Metal Bioremediation

Industrial wastewater produced by electroplating, mining, metal finishing, and related sectors often contains toxic heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), and arsenic (As). These metals are persistent, non-biodegradable, and capable of bioaccumulation, posing serious risks to ecosystems and human health. While conventional physicochemical methods chemical precipitation, membrane separation, ion exchange, and adsorption remain widely used, they suffer from high operational cost, sludge generation, limited selectivity, and poor performance in complex wastewater matrices. Microbial bioremediation has emerged as a sustainable alternative. Bacteria remove metals through biosorption, bioaccumulation, bioprecipitation, and nanoparticle formation. Recent advances in nanotechnology and synthetic biology have enabled the development of nanostructured and genetically modified bacterial strains with enhanced selectivity, faster metal uptake, and improved stress tolerance. This review summarizes current knowledge on microbial mechanisms, nanostructuring strategies, genetic engineering approaches, and the comparative advantages and limitations of various bacterial systems. Despite existing safety concerns and regulatory challenges, engineered and nanostructured bacteria represent a promising frontier for scalable and cost-effective heavy metal removal from industrial wastewater.

کلیدواژه ها:

Heavy metals ، Bioremediation ، Nanostructured bacteria ، Engineered bacteria ، Industrial