Plastic pollution has become an increasingly pressing issue with no clear foreseeable solution to alleviate the significant environmental damage it has caused. Polyolefins, such as polyethylene, are especially harmful due to the lack of heteroatoms in their polymer backbone, making them particularly resistant to both chemical and biological degradation.
Recently, evidence of polyethylene ingestion and catabolism have been observed in the larvae of two wax moth species, Galleria mellonella and Achroia grisella. Several enzymes originating from the saliva of G. mellonella have been identified and verified to degrade polyethylene via oxidation of the backbone and experimental evidence of high-density polyethylene breakdown by A. grisella larvae has also been reported. Hence, these insects have become attractive organisms for plastics bioremediation research.
As the mechanism of plastics biodegradation via these insect larvae is currently poorly understood, resources obtained from multiomic analyses can provide insights into the genes and proteins involved in the process. Transcriptomic studies of the salivary glands and gut tissue of both species revealed various upregulated, tissue-specific enzymes potentially involved in plastics degradation. Subsequently, proteomic analyses of plastic-fed G. mellonella larvae reinforced the comparative transcriptomic results, identifying upregulated proteins such as cytochrome P450 monooxygenases, reductases and dehydrogenases in polyethylene-fed larvae relative to larvae fed laboratory diet.
These results serve as useful resources for both organisms, particularly for future studies investigating individual enzymes to elucidate the biochemical mechanism of plastic breakdown harnessed by these insects.