Improving efficiency of bacterial degradation of polyethylene microplastics using atmospheric and room temperature plasma mutagenesis
Zhuang Xiong, Xiaodie Chen, Ziping Zou, Lianxin Peng, Liang Zou, Bingliang Liu, Qiang Li
Abstract
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.