Improving efficiency of bacterial degradation of polyethylene microplastics using atmospheric and room temperature...

In this study, the bacterium XZ-A was genetically modified using atmospheric and room temperature plasma mutagenesis (ARTP) to increase the degradation efficiency of polyethylene microplastics (PE-MPs) by up to 53.65 %. After 50 d of biodegradation, the mutagenized bacterium XZ-60S caused significant changes in the morphology, structure, thermal stability, and molecular weight of PE-MPs. The number average molecular weights and weight average molecular weights of the PE-MPs were significantly reduced by approximately 15.21 % and 4.80 %, respectively. Comparative genomic and transcriptomic analyses showed that XZ-60S had a total of 106 single nucleotide polymorphic sites, and the expression of genes encoding laccases was significantly increased; this may explain the improved degradation of PE-MPs by XZ-60S. In this study, the degradation of PE-MPs by bacteria was improved through ARTP mutagenesis, which provides a reference for selecting and breeding bacteria that are highly efficient at degrading PE-MPs.