Construction of Yarrowia lipolytica for degradation of low-density polyethylene

The current extensive production and widespread use of polyethylene (PE) has resulted in the accumulation of its waste in the environment, posing a significant threat to the global ecosystem and human health. Biodegradation is regarded as an environmentally sustainable approach for plastic waste treatment. However, achieving high biodegradation efficiency of PE is primary challenge. In this study, the engineered Yarrowia lipolytica strains, expressing heterologous PE-degrading enzymes, were successfully constructed for enhancing degradation of pretreated low-density polyethylene (LDPE) at room temperature. SEM results showed significant changes in surface roughness and erosion of pretreated samples after incubation with the engineered strains of alkane hydroxylase-secreting YPE04 and laccase-secreting YPE10. Notably, YPE04 and YPE10 reduced the weight of LDPE films by 8.9 +/- 0.9 % and 11.8 +/- 0.7 %, respectively, within 7 days. It was further clarified by GC-MS that the main degradation products of LDPE films by the aforementioned two engineered strains were 9-octadecenoic acid and n-dodecyl methacrylate, respectively. Overall, two strains, YPE04 and YPE10, were obtained with great potential for LDPE degradation. This study not only provides a reference for the construction of efficient PE- degrading strains but also offers new ideas for the application of bioremediation technology in plastic waste management.