The effective and green biodegradation of polyethylene microplastics by the screening of a strain with its degrading enzymes

The polyethylene microplastics (MPs) degrading fungi named the strain DL-1 were isolated and screened to reduce the pollution of polyethylene MPs. The strain was preliminarily identified as Aspergillus niger by the sequence homology comparison and phylogenetic tree construction. The biodegradation rate of polyethylene MPs by the strain DL-1 was 7.65 ± 0.92 % after 30 days. The grooves and wrinkles appeared on the surface of MPs after the degradation. During the effective degradation process, the strain DL-1 produced the enzymes (plastic degrading enzymes) to biodegrade the polyethylene MPs. It was showed that the plastic degrading enzymes increased under the induction of polyethylene MPs in the medium, indicating that the enzymes played the important role in biodegradation of polyethylene MPs. Moreover, the ability of strain to biodegrade polyethylene MPs and the mechanism of biodegradation were investigated with varied measurements and characteristics. It enriched the way of microbial degradation of polyethylene MPs and provided the environmentally-friendly biodegradation with the green treatment for MPs.