Biodeterioration of Microplastics: A promising step towards Plastics Waste Management

Abstract

Polyethylene and Polyester materials are resistant to degradation and found as significant source of microplastics pollution, which is emerging concern. In the present study, potential of dumped site bacterial community was evaluated. After primary screening it was observed that 68.5% were linear low-density polyethylene, 33.3% were high-density and 12.9% were Polyester degraders. Up to five strains were chosen for secondary screening, where they were monitored by FTIR, SEM and weight loss degradation trials. Major results were observed by Alcaligenes faecalis (MK517568) and Bacillus cereus (MK517567), as they show highest degradation activity among others. Alcaligenes faecalis (MK517568) degrade LLDPE by 3.5%, HDPE by 5.8% and Polyester by 17.3%. Bacillus cereus (MK517567) better tolerated at 30oC and degrade Polyester by 29%. Changes in infrared spectra indicated degradation pathways of different strains with types of plastics targeted. Through SEM analysis, groves, piths and holes were observed on surface. These findings suggest that soil bacteria develop effective mechanism for degradation of microplastics and beads that enables them to utilize plastics as source of energy without need of pre-treatments, which highlights importance of these soil bacteria for fate of effective plastic waste management in soil environment.