Produção de enzimas lignocelulolíticas por fermentação em estado sólido de resíduos agroindustriais sob ação do fungo Psilocybe castanella CCIBt 2781.

Abstract

This study aimed to produce the enzymes laccase and endoglucanase (CMCase) by solid state fermentation (SSF) using agro-industrial residues by the action of the fungus Psilocybe castanella CCIBt 2781. Fungus was previously grown on 2% MEA substrates and inoculated into the background of green maize straw supplemented with sugar cane bagasse and coconut supplemented with soybean meal in the proper proportions to obtain C/N 90, mediators vegetable oil (1 ml), Tween 80 (0,1 mL), RBBR 2% (1 mL) and 70% humidity at 28°C for 60 days. The enzyme extraction was performed in sodium acetate buffer, pH 4,8. The laccase activity was determined by oxidation of ABTS, and the activity of endoglucanase determined by dosage of the reducing sugars produced in the enzymatic degradation of carboxymethylcellulose (CMC). Obtained the production of laccase by the fungus Psilocybe castanella CCIBt 2781 under different culture conditions. A higher yield was achieved when the medium was supplemented with soy. The peak activity of laccase occurred around the 30th day of fermentation (113,12 U/L), containing coconut oil as carbon source, supplemented with soy as nitrogen source, under the action of all mediators. For the substrate from corn and sugarcane, the highest values of activity was 98,25 U/L in 60 days for the same treatment. Maximising production of endoglucanase (0,29 U/g) was observed only for the substrate from corn and sugar cane, in 45 days, under the influence of textile dye RBBR. These results show that the bioconversion of these wastes in solid state fermentation (SSF) is a feasible way of obtaining lignocellulolytic enzymes form and have applicability in biotechnology field. The results of this study also allowed to show the ability of P. castanella CCIBt 2781de degrade Remazol Brilliant Blue R dye in used culture medium during the time interval of 45 days, resulting in complete decolorization after this period.