Production and application of inulinase by new isolates of Aspergillus welwitschiae from fermented peach-palm waste for the production of fructooligosaccharides

Abstract

Microbial inulinase enzymes have a number of applications in biotechnology. In this study, new strains of Aspergillus welwitschiae were investigated as producers of inulinases and their endo- and exo-inulases were characterized in silico and their protein modeling was performed. The inulinase production by A. welwitschiae employing the Dohelert method to assess the interaction between temperature and cultivation humidity, resulted in a fourfold increase in activity. The optimal temperature and humidity were 25–27 °C and 75–82 %, respectively. The enzyme exhibited optimal activity at a pH of 3.5 and at 60 °C. The hydrolysis of the sisal root yielded 272 mg/g of reducing sugars and oligosaccharides. Our in silico experiments predicted 10 well-validated structures of endo- (5) and exo-inulinases (5) from A. welwitschiae. The notable activity of these inulinases on inulin highlights their potential for the treatment of agro-industrial residues with the objective of producing high-value added products.