Production and mechanical evaluation of biodegradable composites by white rot fungi

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.

Production of biocomposites from the reuse of coconut powder colonized by Shiitake mushroom

“…However, the increase in the cultivation period from 30 to 45 days of complete colonization may have resulted in reduced nutrient availability for microbial metabolism, and in the lower mass loss of the composite colonized by LED CHI and LED 96/18, when compared to 30 days. Teixeira et al (2018) observed a composite mass loss of 72.4%, on average with the isolates of P. sanguineus, Pleurotus spp. cultivated also in coconut powder-based substrate with wheat bran, which represents greater mass loss than that of composites colonized by L. edodes, probably due to the higher rate of degradation of the composite by the isolates tested by Teixeira et al (2018).…”

“…Teixeira et al (2018) observed a composite mass loss of 72.4%, on average with the isolates of P. sanguineus, Pleurotus spp. cultivated also in coconut powder-based substrate with wheat bran, which represents greater mass loss than that of composites colonized by L. edodes, probably due to the higher rate of degradation of the composite by the isolates tested by Teixeira et al (2018).…”

“…Sales-Campos and Andrade (2011) mentioned that the Lentinus strigosus fungi resulted in loss of mass of the substrate culture between 42.2% and 58.6% of wood residues. And Teixeira et al (2018) mentioned that the cultivation period may influence in mass loss of fungal composites with white rot fungi.…”

“…In order to reduce environmental contamination, the green composite is produced from the mixture of vegetable fibers with EPS (Fernandes et al, 2017;Zhang et al, 2016). Alternatively, edible fungi and/or white rot fungi as: Agaricus bisporus (Román-Ramos; Luna-Molina; Bailón-Pérez, 2014), Pleurotus eryngii (Hemmati;Garmabi, 2012), P. ostreatus (Teixeira et al, 2018), Phaenerochaete chrysosporium (Ramirez-Chan et al, 2014) and Pycnoporus sanguineus (Teixeira et al, 2018) were used at production of composites through its reutilization as agricultural residues.…”

“…The company named Ecovative also produces bio-packages colonized by filamentous fungi, but uses composting and pasteurization in the substrate preparation (Zeller;Zocher, 2012), which increases the required time to obtain the bio-packages in relation to the axenic process performed in which it is used autoclaving as mentioned in the patent developed by the following authors (Marino et al, 2017a;Teixeira et al, 2018) with the cultivation of Pleurotus ostreatus, P. eryngii and Pycnoporus sanguineus in coconut powder supplemented with wheat bran.…”