Caracterização Bioquímica das Poligalacturonases produzidas pelos fungos Aspergillus japonicus e Aspergillus sp. M1 e sua apicação na clarificação da polpa da manga

Abstract

Pectinases are a group of enzymes capable of degrading polysaccharides in the plant cell wall, making it easier for microorganisms to obtain a carbon source as a result of cell fragmentation. Filamentous fungi are the most used for enzymatic production on an industrial scale, with application in the clarification of fruit juices, among these are the fungi of the genus Aspergillus. The objective was to evaluate the production and characterize the pectinases produced by Aspergillus japonicus and Aspergillus sp. M1 from agro-industrial residues and apply these enzymes in the clarification of mango juices. The production of pectinase was evaluated using different carbon sources in solid medium (2.5 grams) and the fungi were inoculated with 10 ml of saline solution with spores. The optimal growth time was evaluated using Tereré herb residue as a carbon source in solid medium for 192 h in stationary condition at 35 °C. Enzyme activity was measured at temperatures between 30 and 70 °C and McIlvaine buffer pH 3 to 7 using the DNS method. The clarification of the juice by pectinases was evaluated by measuring the transmittance according to Rosmine et al. (2017). Aspergillus sp. M1 had optimal production in Tereré herb residue after 72h of growth and maximum activity at pH 3 (2.58 U/ml) and 70°C (4.32 U/ml). A. japonicus had optimal production in Tereré grass residue after 48h and maximum activity with McIlvaine buffer pH 3 (1.34 U/ml) and at 60 °C (2.16 U / ml). Pectinase from A. japonicus and Aspergillus sp. M1 obtained maximum results in the clarification of 'Palmer' mango juice at 50 °C, with a clarification of 20.1% ±1.4 and 22.1% ±2.9, respectively. The results showed that pectinases from both fungi present viable characteristics for application in the clarification of fruit juices.