Avaliação do potencial de fungos endofíticos e fitopatogênicos em relação à produção da enzima cutinase

Abstract

The use of plastic started in the last century and has been increasingly used over the years causing extremely relevant impacts related to environmental contamination. Nowadays, the most widely used approach for removing this material from circulation is the waste disposal in landfills or dumps. The use of enzymes capable of degrading this material stands out as a sustainable strategy to help reduce this worldwide problem of plastic waste accumulation. The aim of this study was to identify the capacity of endophytic fungi and phytopathogenic fungi (genus Fusarium) in relation to cutinase production, in order to select a prominent strain for application in the polyethylene terephthalate (PET) hydrolysis. For this the fungi were cultivated in solid and submerged state, containing different carbon sources and nutrients. For both bioprocesses, the results obtained by phytopathogenic strains were superior to those obtained by endophytic strains. For the submerged cultivation, the strain Fusarium oxysporum stood out reaching an enzyme activity of 17.2 IU / mL after 48 h of cultivation, but there was no experimental reproducibility for this condition. Solid state cultivation was promising for the production of cutinase in the absence of nutrient solution, positive result was obtained for 4 of the 5 strains tested. The best cutinase activity obtained using wheat bran and distilled water was for the strain Fusarium poliferatum with an activity of 228 IU/g after 120 h of cultivation. When plastic (PET) was added to the medium, the strain Fusarium solani stood out with the best cutinase activity reaching 318 IU / g. The results indicate that the strains used in the present work are promising for the production of cutinase, with PET being a potential inducer in the production of this enzyme when used in solid cultivation.