Convenient Partial Purification of Glucose Oxidase from <i>Aspergillus niger</i> A9 Fermentation Broth by Reversed Micelles

Abstract

Aim of this work was to establish the optimum conditions for the extraction and recovery by cationic reversed micelles of glucose oxidase (GOX) from Aspergillus niger A9, The influence of pH, temperature, solvent/co-solvents ratio on the extraction was investigated by experiment, using the residual enzyme activity to evaluate the results. The best condition for GOX extraction were ensured using iso-octane as solvent and butanol and n-hexanol co-solvent at 76/18/6 volume ratio, pH 4.80, 200mM cetyl-trimethyl ammonium bromide (CTAB) as cationic surfactant, The enzyme activity of GOX is measured by DNS method (3,5-dinitro salicylic acid method). In the extraction process, ultrasonic oscillation was adopted to mix organic solvent and water, ultrasonic oscillation temperature is 45 °C. Protein activity recovery of GOX can reach 88.2% in extraction.