Recovery of pectinases from Aspergillus niger using aqueous two-phase systems / Recuperação de pectinases de Aspergillus niger usando sistemas aquosos bifásicos

Abstract

This work aimed to study the purification of pectinases by aqueous two-phase systems (ATPS). The crude enzymatic extract was produced by Aspergillus niger ATCC 9642 and contained exo-polygalacturonase (exo-PG), pectinmethylesterase (PME) and pectin lyase (PMGL). The ATPS systems tested consisted in the combinations of polyethylene glycol (PEG) and potassium phosphate and sodium citrate, alcohol (ethanol, n-propanol and isopropanol) and salt (ammonium sulfate, potassium phosphate and sodium citrate). The experiments showed higher recoveries using ATPS system - PEG/phosphate for the exo-PG were using 16% PEG 4.0 kDa/4.8% NaCl and 16% PEG 1.5 kDa/without NaCl, obtaining purification factors (PF) of 1.37 and 1.21 times and recovery (R) of 49 and 59%, respectively. However, for the enzymes PME and PMGL were of 4.8 and 4.7 fold and 478 and 241%, respectively. When used ATPS system - PEG/sodium citrate the best PF were of 2.4, 7.85 and 5.7 and R of 100, 331 and 239% for exo-PG, PME and PMGL, respectively. The ATPS system is an alternative and efficient method for the recovery and/or purification of pectinases. This work aimed to study the purification of pectinases by aqueous two-phase systems (ATPS). The crude enzymatic extract was produced by Aspergillus niger ATCC 9642 and contained exo-polygalacturonase (exo-PG), pectinmethylesterase (PME) and pectin lyase (PMGL). The ATPS systems tested consisted in the combinations of polyethylene glycol (PEG) and potassium phosphate and sodium citrate, alcohol (ethanol, n-propanol and isopropanol) and salt (ammonium sulfate, potassium phosphate and sodium citrate). The experiments showed higher recoveries using ATPS system - PEG/phosphate for the exo-PG were using 16% PEG 4.0 kDa/4.8% NaCl and 16% PEG 1.5 kDa/without NaCl, obtaining purification factors (PF) of 1.37 and 1.21 times and recovery (R) of 49 and 59%, respectively. However, for the enzymes PME and PMGL were of 4.8 and 4.7 fold and 478 and 241%, respectively. When used ATPS system - PEG/sodium citrate the best PF were of 2.4, 7.85 and 5.7 and R of 100, 331 and 239% for exo-PG, PME and PMGL, respectively. The ATPS system is an alternative and efficient method for the recovery and/or purification of pectinases. This work aimed to study the purification of pectinases by aqueous two-phase systems (ATPS). The crude enzymatic extract was produced by Aspergillus niger ATCC 9642 and contained exo-polygalacturonase (exo-PG), pectinmethylesterase (PME) and pectin lyase (PMGL). The ATPS systems tested consisted in the combinations of polyethylene glycol (PEG) and potassium phosphate and sodium citrate, alcohol (ethanol, n-propanol and isopropanol) and salt (ammonium sulfate, potassium phosphate and sodium citrate). The experiments showed higher recoveries using ATPS system - PEG/phosphate for the exo-PG were using 16% PEG 4.0 kDa/4.8% NaCl and 16% PEG 1.5 kDa/without NaCl, obtaining purification factors (PF) of 1.37 and 1.21 times and recovery (R) of 49 and 59%, respectively. However, for the enzymes PME and PMGL were of 4.8 and 4.7 fold and 478 and 241%, respectively. When used ATPS system - PEG/sodium citrate the best PF were of 2.4, 7.85 and 5.7 and R of 100, 331 and 239% for exo-PG, PME and PMGL, respectively. The ATPS system is an alternative and efficient method for the recovery and/or purification of pectinases