Enzymatic Synthesis of Alkyl Glycosides with Ionic Liquid as a Modulator

3 Enzymatic Synthesis of Alkyl Glycosides with Ionic Liquid as a Modulator 

An immobilized enzyme is an enzyme that is attached to an inert, insoluble material to provide inereased resistance to changes in reaction conditions such as pH or temperature. Additionally, it allows enzymes to be trapped in a reaetor throughout the reaction, following which they are easily separated from the produets and may be recycled for utilization. Therefore, immobilized biocatalysts may represent the earliest and easiest ways to modulate the performanee of native enzymes for application in industry due to its economical end. 

There are three different ways to immobilize an enzyme, whieh are as follows  

1 Reactors with Immobilized Enzymes on Classic Supports 

Various materials have been used as supports for the immobilization of a Candida rugosa lipase (Lipase OF). The enzyme adsorbed on silica gel showed the maximum activity recovery (37%), and was thus used to construct a packed bed reactor for the continuous production of (S)-ketoprofen. The performance of the bioreactor containing 4.0 g of immobilized biocatalyst was evaluated as a function of parameters such as flow rate, the ratio of height to diameter [H/D] and substrate concentration. The space velocity (SV) of the reactor showed a linear increase when the flow rate was increased in the range of 5.9-25 mL h (SV = 0.9-3.9 h ) and leveled out at values for flow rate between 25 (SV = 3.9 h ) and 64 mL h (SV = 10.2 h ). The initial rate remained the same when the HID was varied from 2.9 to 38.6. The initial rate rose linearly as the substrate concentration was increased from 5 to 20 mg mL and remained almost at the same level when the substrate concentration was between 20 and 50 mg mL. Using a packed bed bioreactor, optically pure (S)-ketoprofen ( 99% ee) was produced with a conversion of 30% and productivity of 1.5 mg per gbiocataiyst per h. 

---