Production and mechanical evaluation of biodegradable composites by white rot fungi

Produção e avaliação mecânica de compósitos biodegradáveis por fungos de podridão branca

ABSTRACT

The production of plastic packing grows worldwide, resulting in the accumulation of these materials in the environment due to improper disposal and problems related to degradation. Alternatively, composites produced with agricultural residues and filamentous fungi may exhibit physical and mechanical properties similar to or greater than expanded polystyrene, depending on the fungal species and substrate of the cultivation. In the literature, no reports were found on the use of coconut powder and edible fungi of white rot in the mechanical properties of composites. Thus, the objective of this work was to select fungal isolates and to evaluate the period of cultivation in the mechanical resistance of composites produced in coconut powder supplemented with wheat bran. The experimental design was completely randomized in a 5 x 3 factorial scheme corresponding to the cultivation of five edible fungal isolates (Pleurotus ostreatus: POS-W, POS-SP1, POS-98/38; Pleurotus eryngii: POS ER and Pycnoporus sanguineus: PS) and three culture periods after complete colonization of the substrate (15, 30 and 45 days), with four replications. The period of cultivation of the fungal isolates may influence in the composite mass loss and volume loss. The compressive strength and tenacity of the composite are influenced by the fungal isolate and the time of cultivation. The isolates of Pycnoporus sanguineus, Pleurotus ostreatus and P. eryngii present potential characteristics for the production of biodegradable composites.

Index terms:
Biotechnology; edible fungi; coconut powder.