Application of beta-glucuronidase-immobilised silica gel formulation to microfluidic platform for biotransformation of beta-glucuronides

To improve the efficiency of reactions of beta-glucuronidase (GUS)-assisted glucuronic acid (GluA) removal within a microfluidic system. beta-glucuronidase from Helix pomatia was immobilised and characterised in silica-based sol-gel monoliths. Efficiency of the GUS-doped silica monoliths was tested for hydrolysis of p-Nitrophenyl-beta-d-glucuronide (pNP-GluA) in both ml-scaled medium via batch reactions and microfluidic environment via continuous-flow reactions. In the microfluidic platform, within a duration of 150 min of continuous operation (flow rate: 1 A mu L/min), the obtained highest pNP yield was almost 50% higher than that of the corresponding batchwise reaction. However, increased flow rates (3, 5, and 10 A mu L/min) resulted in lower conversion yields compared to 1 A mu L/min. The microfluidic platform demonstrated continuous hydrolytic activity for 7 days with considerable reaction yields while using a small amount of the enzyme. These results revealed that usage of the microreactors has considerable potential to efficiently obtain bioactive GluA-free aglycons from various plant-derived beta-glucuronides for pharmaceutical applications. [GRAPHICS] .