Desenvolvimento de processo biotecnológico para obtenção de frutosiltransferase a partir de linhagens de aspergillus spp. utilizando resíduos agroindustriais

Abstract

Fructosyltransferase is an enzyme involved in the conversion of sucrose to fructooligosaccharides, sugars that have received special attention because to their biological and functional properties, which act mainly as prebiotics. This enzyme, as well as other biomolecules can be obtained through biotechnological processes, using several types of microorganisms, among these processes, solid-state fermentation stands out because it allows the use of agroindustrial residues, besides promoting high production rates of biomolecules of interest. The present study had as objective to investigate the variables that influence the production of fructosyltransferase from Aspergillus spp. using agroindustrial residues as well as characterize the crude extract. The best results were found in the species Aspergillus tamarii URM4634, to which it did not show production of mycotoxins, fermented in the soybean meal. From the factorial design it was verified that the best condition was observed using 3 g of substrate, 15% concentration of sucrose solution and 60% of moisture for 72 hours, obtaining 209.11 and 53.90 μmol / mL / min of hydrolytic and transfructosylation activities, respectively. In the evaluation of the growth of fungal biomass, the highest development in 36 hours of fermentation, observing a content of 132 mg / g of glucosamine, in this same analysis it was verified that the best time for production of fructosyltransferase, using the conditions of the best condition of planning were obtained in the 96-hour period, obtaining 221.53 and 66.90 μmol / mL / min of hydrolytic and trans-fructosylation activities, respectively. The enzyme produced presented values of Km 54.73 and 369.68 μmol/mL and Vmáx 227.27 and 50.66 μmol/mL/min for hydrolytic and transfructosylation activities, respectively. The optimal temperature for both activities was 60ºC, as well as pH 6.0. The fructosyltransferase presented stability in the temperature ranges of 30-50 ° C and pH 4.0-5.0. It was also observed that the Mn2 + ion showed to be an activator of the hydrolytic activity, whereas Na + presented the same effect in the transfructosylation activity. In general, all results are promising for the biotechnological production of fructosyltransferase, demonstrating high saccharose hydrolysis and transfer of the fructosyl groupings, potentially being applied in bioprocesses that aim at the synthesis of fructo-oligosaccharides.