A simplified and miniaturized glucometer-based assay for the detection of β-glucosidase activity / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

β-Glucosidase activity assays constitute an important indicator for the early diagnosis of neonatal necrotizing enterocolitis and qualitative changes in medicinal plants. The drawbacks of the existing methods are high consumption of both time and reagents, complexity in operation, and requirement of expensive instruments and highly trained personnel. The present study provides a simplified, highly selective, and miniaturized glucometer-based strategy for the detection of β-glucosidase activity. Single-factor experiments showed that optimum β-glucosidase activity was exhibited at 50 °C and pH 5.0 in a citric acid-sodium citrate buffer when reacting with 0.03 g/mL salicin for 30 min. The procedure for detection was simplified without the need of a chromogenic reaction. Validation of the analytical method demonstrated that the accuracy, precision, repeatability, stability, and durability were good. The linear ranges of β-glucosidase in a buffer solution and rat serum were 0.0873-1.5498 U/mL and 0.4076-2.9019 U/mL, respectively. The proposed method was free from interference from β-dextranase, snailase, β-galactosidase, hemicellulase, and glucuronic acid released by baicalin. This demonstrated that the proposed assay had a higher selectivity than the conventional dinitrosalicylic acid (DNS) assay because of the specificity for salicin and unique recognition of glucose by a personal glucose meter. Miniaturization of the method resulted in a microassay for β-glucosidase activity. The easy-to-operate method was successfully used to detect a series of β-glucosidases extracted from bitter almonds and cultured by Aspergillus niger. In addition, the simplified and miniaturized glucometer-based assay has potential application in the point-of-care testing of β-glucosidase in many fields, including medical diagnostics, food safety, and environmental monitoring.

Study on hydrolysis of baicalin into baicalein by immobilized beta-glucosidase in a two-phase system / 中国中药杂志

The optimum conditions of baicalin hydrolysis into baicalein by immobilized beta-glucosidase in a two-phase system was studied and the yield was observed. A two-phase system comprising of sodium acetate buffer and chloroform was determined by comparing the solubleness of baicalein in different solvents and partition coefficient of baicalein in related aqueous-organic two-phase system. beta-Glucosidase was immobilized by the crosslinking-embedding method using sodium alginate as the carrier The optimum reaction temperature, pH value, Michaelis constant, the thermal stability and pH stability were assayed. By comparing the yield of baicalin hydrolysis into baicalein by immobilized beta-glucosidase in two-phase system, the optimum reaction conditions were determined-the optimum reaction temperature, pH value and time were 50 degrees C, 5.0 and 10 h, respectively. The yield of baicalein was 85.28%. Compare with one-phase system, two-phase system had an advantage in reaction rate and yield.