Potential strategies for bioremediation of microplastic contaminated soil

Abstract

The escalating production and ubiquitous presence of plastics and their degradation products, such as microplastics and nanoplastics, pose a significant environmental threat. Microplastics enter the soil through various pathways, including agricultural practices, plastic degradation, and wastewater disposal. Herein, we discussed the harmful effects of microplastics on the physicochemical properties of soil, plant growth, terrestrial fauna, and microbial activity, potentially affecting the stability and nutrient cycle of the soil ecosystem. This review delves into recent advances in potential microplastic bioremediation approaches, such as phytoremediation strategies utilized by plants and their associated microbes to accumulate, immobilize, and even degrade microplastics. Rhizosphere microorganisms play a crucial role in the degradation of microplastics, potentially utilizing them as a carbon source. Soil animals like earthworms, snails, and mealworms can also contribute significantly to bioremediation by ingesting and degrading microplastics through their gut microbiota. Various soil microorganisms, including bacteria and fungi, can degrade different microplastics with the help of enzymes such as laccase, esterase, peroxidase, oxidoreductase, and hydrolases and depolymerise the larger polymer chains into smaller units that ultimately mineralize them into CO2, H2O, and CH4. Genetic engineering and synthetic biology are also used to create strains with enhanced microplastic degrading and mineralization capabilities. It holds promise for efficient bioremediation but requires further research for real-world application and scalable implementation. Overall, this review comprehensively highlights the potential of bioremediation approaches and future recommendations for tackling microplastic pollution. Further research and development are crucial for enhancing biodegradation efficiency and scaling up this strategy for environmental protection.