Evaluation of Galleria mellonella immune response as a key step toward plastic degradation

Background Plastic's remarkable durability presents a significant challenge for our planet, leading to widespread environmental damage. However, some organisms, such as Galleria mellonella larvae, have shown a unique capability to consume and degrade plastic, offering potential solutions to plastic pollution. In this study, we investigated the response of G. mellonella larvae to different diets, including artificial diet (AD), polyethylene low density mixed with AD (PELD + AD), and PELD alone. Using various microscopy techniques, we examined the larvae's hemocyte hemogram and mid-gut characteristics to understand their immune response and digestive system when exposed to plastic.Results The results revealed that PELD-only feeding negatively impacted hemocyte immunity, resulting in a significant decrease in total hemocyte counts compared to AD and AD + PELD feeding. Moreover, plastic consumption induced differential hemocyte alterations, affecting specific cell types. The presence of phagosomes in larval hemocytes and mid-gut cells during PELD-only feeding suggested active involvement in plastic breakdown.Conclusions These findings highlight the potential of G. mellonella larvae as a model organism to study responses to pollutants, emphasizing the urgent need to address plastic pollution's global threat. Further investigation is warranted to explore larval deformities, weight loss, and appetite changes, potentially influencing mortality rates and enzyme biochemistry. Understanding the impacts of plastic ingestion on G. mellonella larvae is crucial to develop effective strategies for mitigating plastic pollution's ecological implications.