Mukul

Industrial wastewater sludge can accumulate microplastics and other contaminants, creating a complex matrix for remediation. This review examines microbial strategies for polyethylene (PE) degradation in sludge and considers how genetic engineering could improve their industrial feasibility. Literature was identified through Google Scholar, PubMed, ScienceDirect, and JSTOR using searches covering PE biodegradation, Pseudomonas putida, alkB, microplastic bioremediation, heavy-metal co-toxicity, and metabolic engineering. The reviewed evidence highlights PE's chemically inert carbon-carbon backbone, the reported potential of microbial isolates, and the additional constraints imposed by heavy metals and other co-contaminants. The paper focuses on Pseudomonas putida and Pseudomonas stutzeri, together with proposed laccase, alkB, and metal- resistance strategies, as candidate components of engineered treatment systems. The evidence also indicates that laboratory observations cannot yet be treated as proof of industrial-scale performance in complex sludge. Overall, engineered microbial systems may provide a future route to PE treatment, but their practical value depends on validated degradation mechanisms, performance in real sludge matrices, process economics, and effective biosafety and biocontainment controls.