Biodegradation of polyethylene microplastic particles by the fungus Aspergillus flavus from the guts of wax moth Galleria mellonella

• Published in: The Science of the total environment 2020-02, Vol.704, p.135931-135931, Article 135931
• Main Authors: Zhang, Junqing, Gao, Danling, Li, Quanhao, Zhao, Yixuan, Li, Li, Lin, Hanfeng, Bi, Qirui, Zhao, Yucheng
• Format: Article
• Language: English
• Subjects: Animals; Aspergillus flavus; Aspergillus flavus - metabolism; Biodegradation; Biodegradation, Environmental; Environmental Pollutants - metabolism; Galleria mellonella; Gastrointestinal Contents; Microplastic particles; Microplastics - metabolism; Moths - microbiology; Polyethylene - metabolism; Polyethylene degrading enzyme
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2019.135931

Polyethylene (PE) products are widely used in daily life, agriculture, and industry because of their convenience and economic value. However, PE is one of the polymer materials remarkably resistant to degradation. Current methods of plastic waste disposal pose a threat to the environment and produce microplastic particles (MPP), which becomes a global environmental concern because of its accumulation. In this study, a PE-degrading fungus Aspergillus flavus named PEDX3, was isolated from the gut contents of wax moth Galleria mellonella. The results indicated that high-density polyethylene (HDPE) MPP was degraded into the MPP with a lower molecular weight by strain PEDX3 after 28 days incubation. In addition, Fourier Transform - Infrared Spectroscopy (FT-IR) results showed the appearance of carbonyl groups and ether groups of MPP, which also validated the degradation of PE. Furthermore, the potential degradation enzymes were investigated by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Finally, two laccase-like multicopper oxidases (LMCOs) genes, AFLA_006190 and AFLA_053930, displayed up-regulated expression during the degradation process, which may be the candidate PE-degrading enzymes. These results have demonstrated that the A. flavus strain PEDX3 has an ability to degrade microplastic particles and the two PE-degrading enzymes provide a promising application for the PE MPP remediation. [Display omitted] •Aspergillus flavus was isolated from the guts of wax moth Galleria mellonella.•The HT-GPC and FTIR results showed the biodegradation of polyethylene microplastics.•Two laccase-like multicopper oxidases (LMCOs) displayed up-regulated trends.•The results highlight the potential of LMCOs as tools for microplastic remediation.