Amyloid-Like Self-Assembling of Black Soldier Fly Proteins and Development of Bioplastics

The rising demand for sustainable materials has increased interest in biodegradable plastics. The black soldier fly (BSF) is a protein source characterized by the ability to thrive on organic waste, rapid development, and low environmental impact. This study shows that BSF proteins can undergo amyloid-like aggregation in alkaline environments, ultimately leading to amyloid fibrils suitable as reinforcing nanofillers for bioplastic films. The fibrillization process was monitored through Thioflavin-T (ThT) fluorescence assay and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The fibrils' structure was studied by means of transmission electron microscopy (TEM) and one-dimensional/two-dimensional (1D/2D) X-ray diffraction (XRD) analyses performed on films obtained by casting. Bioplastic films were prepared by blending fibrillizated BSF proteins with poly-(vinyl alcohol) (PVOH) and glycerol. They exhibited thermal weldability and mechanical and gas barrier properties in line with those of the traditional oil- and biobased plastics used for packaging applications. Due to the current technological interest in BSF as a bioconverter of organic matter, the BSF protein-based materials presented in this work not only could help in mitigating the pressure arising from the accumulation of nonbiodegradable plastics but also provide tangible evidence about the valorization of municipal organic waste.