Piezoelectric sensing of glucose oxidase activity of Aspergillus niger spores pretreated by different methods

Abstract

The development of Aspergillus niger (A. niger) spores as glucose oxidase (GOD) biocatalysts to produce gluconic acid is highly anticipated in the food industry. Herein, a piezoelectric sensor (PIS) method has been developed for the detection of GOD activity and better application of rapid screening of GOD activity in A. niger spores. The GOD activity detection is based on GOD catalyzing β-d-glucose to produce gluconic acid, which results in frequency shift changes recorded by the PIS device in real-time. Using the PIS method, the kinetic parameter 6.5 mg/mL, the correlation equation υ0=31.92CGOD+1.04, the recoveries (89.4%–93.9%, and their RSDs were all within 6.1%) and the optimal GOD activity in A. niger spores under different treatment conditions was obtained. Compared with the classical methods, the proposed method is accurate, rapid, convenient and does not require additional reagents. It has a broad range of potential applications for exploring new GOD biocatalysts.