Development of a Bioreactor-Based Model for low-density polyethylene (LDPE) Biodegradation by Aspergillus brasiliensis

Abstract

Low-density polyethylene (LDPE) is a widely used polymer due to its chemical resistance, high flexibility, and mechanical properties. However, its low degradation rate, coupled with its low lifespan and widespread accumulation, poses significant environmental and public health concerns. This study presents a biodegradation model for LDPE using a suspension bioreactor, which could serve as a biological treatment alternative before polymer disposal. In our model, an initial culture of Aspergillus brasiliensis metabolized the carbon within the polymer structure and used it as an energy source, leading to LPDE biodegradation and mineralization. The procedure took place in a laboratory-scale bioreactor prototype under aerobic conditions and submerged liquid fermentation. After one month of culture, a biodegradation percentage of 1:890:56 % was reached. The treated materials were analyzed by scanning electron microscopy (SEM) and fourier transform infrared spectroscopy (FTIR). We found evidence of biodegradation, colonization of the material, and biofilm formation. This research provides preliminary data on the biodegradation of LDPE under submerged liquid fermentation, marking an initial phase in the development of a prototype for polymer biodegradation.