Hydrolase and plastic-degrading microbiota explain degradation of polyethylene terephthalate microplastics during high-temperature composting

This research aims to explore the degradation properties of polyethylene terephthalate (PET) by PET hydrolase (WCCG) in high-temperature composting and its impact on microbial communities. PET degradation, composting parameters and microbial communities were assessed in 220 L sludge composters with PET and WCCG using high-throughput sequencing. Results showed that WCCG addition led to a deceleration of the humification process and a reduction in the relative abundance of thermophilic genera. Potential PET degrading microbiota, e. g. Acinetobacter, Bacillus, were enriched in the plastisphere in the composters where PET reduced by 26 % without WCCG addition. The external introduction of the WCCG enzyme to compost predominantly instigates a chemical reaction with PET, concurently curtailing the proliferation of plastic-degrading bacteria, leading to a 35 % degradation of PET. Both the WCCG enzyme and the microbiota associated with plastic-degradation showed the potential for reducing PET, offering a novel method for mitigating pollution caused by environmental microplastics.

Automated summary

This research investigated the degradation properties of polyethylene terephthalate (PET) by PET hydrolase (WCCG) in high-temperature composting and its impact on microbial communities. The study found that the addition of WCCG enzyme slowed down the degradation of PET and reduced the abundance of thermophilic bacteria. However, potential PET degrading microbiota, such as Acinetobacter and Bacillus, were enriched in the composters where PET was reduced without WCCG addition. The external introduction of the WCCG enzyme to the compost reacted with PET and inhibited the proliferation of plastic-degrading bacteria, resulting in a 35% degradation of PET. The research suggests that both the WCCG enzyme and the microbiota associated with plastic-degradation have the potential to reduce PET, providing a novel method for mitigating pollution caused by environmental microplastics.