| Congresso Brasileiro de Microbiologia 2023 | Resumo: 358-1 | ||||
Resumo:Proteases (proteolytic enzymes) constitute a large group of enzymes that catalyze the hydrolysis of peptide bonds of proteins into peptides and amino acids and have potential application in the food, detergent and pharmaceutical industries. Filamentous fungi are used in many industrial processes for the production of enzymes. Among the many advantages offered by the production of enzymes by fungi are the low cost combined with high productivity. Thus, the present research aimed at the production and application of protein hydrolysates by proteolytic enzymes of Aspergillus oryzae and Aspergillus niger. As a culture medium to obtain the proteases, coarse rice flour supplemented with 1% peptone and distilled water was used. Each medium was inoculated with a suspension of A. oryzae or A. niger spores (3-4 ml, 105 - 106 spores/g) and the inoculated material was incubated at 24 ºC for 7 days. After 7 days of fungal growth, a crude enzymatic extract was obtained by adding 50 mL of distilled water. The determination of proteolytic activity was performed using azocasein and casein substrates. The antioxidant activity was determined by the ABTS and DPPH methodology. The proteases produced by A. niger and A. oryzae showed stability in the range of 50 to 60 ºC, with a higher activity at 55 ºC. The maximum proteolytic activity of the crude enzymatic extract obtained from A. niger occurred at pH 4.0 and from A. oryzae at pH 7.0. The degree of casein hydrolysis was higher when A. niger proteases (70.86%) were used compared to A. oryzae proteases (30.21 %). The casein hydrolysates produced by both A. oryzae and A. niger showed the highest values of antioxidant activity in the ABTS and DPPH methods (1096.5 - 1336.00; 1061.14-1301.14 Trolox EQ μmol⋅g^−1). The proteases showed activity from 201.4 to 354.2 U using azocasein and activity from 127.6 to 153.4 U using casein, after 60 min of reaction, at a temperature of 35°C. The application of A. oryzae and A. niger proteases in milk coagulation showed that both enzymatic extracts had milk coagulation capacity, with separation between whey and coagulated mass. The results of this work are important for the future applications of these enzymes, which may be used in the production of protein hydrolysates containing bioactive peptides with antioxidant activity. Palavras-chave: Aspergillus, Antioxidant activity, Protein hydrolysate, Bioactive peptide, Fungal protease Agência de fomento:Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES | |||||