Optimization of the plastic biodegradation process through Galleria mellonella larvae and their degradation mechanisms

• Grant number: 24/04597-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: May 01, 2025
• End date: July 31, 2028
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Rondinelli Donizetti Herculano
• Grantee: Betina Sayeg Burd
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Plastic is an integral part of modern society. However, its excessive production and improper disposal contribute to unprecedented pollution. Known for its extremely long-lasting nature, the search for organisms capable of biodegrading plastic in its various forms is growing. In 2017, it was observed that larvae of the moth Galleria mellonella are capable of biodegrading polyethylene, a popular category of plastic. These larvae gained prominence as, in addition to being easy to cultivate, they are avid devourers of the polymer. In the following years, several studies on their biodegradation mechanisms were published, identifying and characterizing enzymes and microorganisms responsible for the depolymerization of various types of plastic. Despite the promising results already described, much remains to be done in terms of optimizing the biodegradation processes of plastic materials, making it essential to search for ways to enhance this degradation capacity. Thus, the present work is justified by the need to optimize the plastic biodegradation process, while making use of the mechanisms already presented by the larvae of G. mellonella. This project proposes to use live larvae, their enzymes and microorganisms, in order to evaluate which configuration is most optimized, followed by a pilot study in a scale-up bioreactor. For this, two types of plastic widely used by the population will be tested, namely polystyrene (PS) and low-density polyethylene (LDPE). Saliva, intestine and feces samples from the larvae will be collected so that enzymes and microorganisms associated with biodegradation can be extracted and used in the experiments. Microorganisms and enzymes already described in the literature will be used, allowing the main focus of the work to be, in fact, on the optimization of the biodegradation process, as well as the tryout tests of the optimized condition.