Microbial transformation of plastics: A possible pathway to sustainable waste reduction

Plastic pollution represents a major global environmental challenge due to the persistence of plastic materials and their widespread use across various sectors.The degradation of plastics can result in the release of microplastics into the environment, leading to food chain disruption, adverse effects on human and animal health, as well as contributing to environmental deterioration and climate change.Therefore, the excessive accumulation of plastic waste poses a significant threat to ecosystems and sustainable development.In this study, six bacterial species and four fungal species were isolated from plastic waste samples to evaluate their potential role in plastic biodegradation.The bacterial isolates were identified as Bacillus altitudinis, Bacillus subtilis, Bacillus velezensis, Micrococcus luteus, Moraxella catarrhalis, and Staphylococcus aureus.Identification was performed using conventional microbiological methods, including colony morphology, Gram staining, cultural characteristics, hemolytic activity, and biochemical tests.The fungal isolates were identified as Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, and Aspergillus terreus.Notably, Aspergillus species were the only fungal isolates recovered, reflecting their ability to tolerate harsh environmental conditions and utilise complex polymeric substrates.Molecular characterisation confirmed the morphological identification of the fungal isolates.Enzymatic analysis revealed that the isolated microorganisms produced manganese peroxidase and lipase enzymes, indicating their potential involvement in plastic degradation.Comparative evaluation demonstrated that the fungal isolates exhibited greater plastic-degrading activity than the bacterial isolates.Among the fungi, A. flavus, A. niger, and A. fumigatus showed the highest biodegradation potential.In contrast, bacterial species displayed relatively lower degradation efficiency.These findings highlight the promising role of naturally occurring microorganisms, particularly Aspergillus species, in the biodegradation of plastic waste and their potential application in sustainable waste management strategies.