Potencial catalítico de amilases produzidas por cultivo em estado sólido dos fungos ‘Monilia sitophila’ e ‘Fusarium verticillioides’

Abstract

Amylases are enzymes of great importance in the market, with applications in the food, pharmaceutical, textile and energy industries. However, the production cost of these enzymes on an industrial scale is still high. Among the existing alternatives to reduce these costs is the use of agroindustrial residues as a substrate in the cultivation of microorganisms. The objective of this work was to optimize amylase production by Monilia sitophila and Fusarium verticillioides, to characterize biochemically produced amylases and to evaluate their catalytic properties. The highest production of amylase by the M. sitophila fungus was obtained using wheat bran, with 60% humidity, 35ºC in 120 hours of cultivation (341.30 U/g) and for the fungus F. verticillioides was obtained using wheat bran, with 70% humidity, 30ºC in 72 hours of cultivation (360.21 U/g). The amylase produced by M. sitophila had higher catalytic activity at pH 4.5 at 60ºC and was stable between pH 3.0-5.5, maintaining its catalytic activity for 1 hour at 50ºC. The amylase produced by the fungus F. verticillioides presented higher catalytic activity at pH 5.0 at 50ºC. This enzyme was stable between pH 5.0-7.0 and maintained its catalytic activity for 1 hour at 45ºC. Both enzymes had the potential to hydrolyze starches from different plant sources. In the results obtained from the thin layer chromatography the presence of exoamylases was observed, as well as the release of glucose monomers.