Biodegradação de polipropileno (PP) e poliestireno (PS) utilizando fungo isolado do trato intestinal de Tenebrio molitor Linnaeus

Abstract

The world has been undergoing environmental changes through population growth, so the high production of solid waste is responsible for such changes. In 2016, 14 million tons of polystyrene and 68 million tons of polypropylene were produced globally, with polypropylene being the second most produced on a global scale, just behind polyethylene (with 116 million tons) while polystyrene appears in the sixth position. The large volume of plastic materials consumed and consequently their post-consumption disposal and an incorrect disposal of them, is one of those related to the environmental impacts caused by the solid waste. In Brazil, the recycling rate for plastic and comparable post-consumer packaging is 25.8% - equivalent to the recycling of 550 thousand tons in 2016. Dedicated to poor waste management, it is estimated that one third of all the discarded plastic has been inserted into nature as terrestrial, freshwater or marine formulations. Most of this waste when mismanaged has enormous potential for polluting terrestrial ecosystems, and 80% of plastics in the oceans come from terrestrial. Given the need to obtain a natural degradation process for thermoplastic compounds, Yang et al. (2015) showed a promising biodegradation agent. This is the Tenebrio molitor Linnaeus, also popularly known as mealworm. This work sought to evaluate the potential biodegradation of polystyrene and polypropylene by a fungus isolated from the intestinal tract of the larva of Tenebrio molitor Linnaeus, in order to investigate a possible alternative for solid waste treatments based on these materials. For the experiment, carried out in the bioprocess laboratory of the Federal Technological University of Paraná, Campus Campo Mourão, a colony of fungi isolated from the intestinal tract of Tenebrio molitor L., from the biological material repository of the laboratory, was used. Polystyrene presented an average value of biodegradation rate of 8.16% while for polypropylene the average value was 5.13%. The minimum value of the biodegradation rate for PS was 4.54% and the maximum was 15.78%, whereas the PP had a minimum and a maximum of 3.70% and 8.69%, respectively. For PS, the standard deviation was 3.39 and the variance was 11.53, in the PP samples, the standard deviation was 1.64 and the variance was in the order of 2.69. The fungi used in the work, from the intestinal tract of the Tenebrio larvae, proved to be efficient in the biodegradation of polystyrene and polypropylene.