Peptidases production by fungi obtained from Manihot esculenta Crantz waste and its application in gluten hydrolysis

Abstract

© 2021 Elsevier LtdThe growing number of people who develop food intolerance has worried researchers around the world. In this context, studies have been developed to find alternatives that minimize the side effects of these disorders. Positive results have been obtained through the enrichment of foods which contain gluten with specific enzymes able to hydrolyze their protein chains. Therefore, this study investigated fungi associated with stems and leaves of Manihot esculenta Crantz waste which produce peptidases capable of hydrolyzing gluten. The peptidase production capacity of the fungi was tested, and the best results were observed for the ST5 fungus (Alternaria sp.) with specific activity of 1.28 ± 0.004 U/mg. For this fungus, tests were carried out and it was verified that pH 3.0 was the best for its growth using sucrose as a carbon source (2.06 ± 0.001 mg/mg of protein). The pre-purification of the enzyme by saline precipitation with ammonium sulphate showed the best activity (81.69 mg/mg of protein) was achieved in the supernatant obtained after saturation of 75.0%. In the gluten hydrolysis reaction, the ideal reaction time was 24 h and the pH approximately equal to 4. In addition, it was demonstrated that the enzymatic activity involved in gluten hydrolysis was blocked by the inhibitor of aspartyl-peptidase-pepstatin.