Microbial Community and Enzymes for Biodeterioration of PVC Plastic Buried in Soil and Compost Environment
摘要
Polyvinyl chloride (PVC) plastic films accumulate in the environment and cause ecological damage due to their persistent, high-density polymeric nature. To mitigate PVC pollution, a sustainable bioremediation approach needs to be designed. Biodegradation of PVC using pure bacterial cultures has been reported as a sustainable option. However, PVC biodegradation studies in the presence of a soil/compost indigenous microbiome have not been conducted. In the present study, attempts have been made to understand and show the biodeterioration and biodegradation of PVC under soil and compost burial conditions. The study revealed that the PVC films, when buried under soil and compost at different conditions (ambient, sun-exposed, and 37 °C conditions), resulted in gravimetric weight loss with CO2 release. Under soil burial at 37 °C, PVC films showed 13.32 ± 0.10% weight reduction with 9.9 ± 0.9% CO2 evolution in 90 days, whereas compost conditions resulted in 6.89 ± 0.11% weight reduction. Another unique feature of the study is the metagenomic profiling of PVC buried soil/compost microbiomes, which revealed Proteobacteria and Actinobacteria as dominant phyla with Bacillus, Staphylococcus, Streptomyces, Arthrobacter, and Exiguobacterium as predominant genera. Also, the bioinformatics analysis revealed that these microbes possess potential metabolic capability associated with PVC biodeterioration and biodegradation (laccases, peroxidases, and oxidoreductases). Overall, the novelty reflects integrating metagenomic, spectroscopic, and morphological characterization of buried PVC plastic and linking microbial community dynamics with their enzymatic machinery and physico-chemical transformations of PVC. These multi-analytical approaches provided mechanistic evidence that the soil/compost microbial community initiates the PVC biodegradation process, offering a scientific basis for designing sustainable plastic waste management and remediation practices.