Encapsulation of β-amylase in water-oil-water enzyme emulsion liquid membrane (EELM) bioreactor for enzymatic conversion of starch to maltose

Abstract

The β-amylase was encapsulated in emulsion liquid membrane (ELM), which acted as a reactor for conversion of starch to maltose. The membrane phase was consisted of surfactant (span 80), stabilizer (polystyrene), carrier for maltose transport (methyl cholate) and solvent (xylene). The substrate starch in feed phase entered into the internal phase by the process of diffusion and hydrolyzed to maltose by encapsulated β-amylase. Methyl cholate present in the membrane acts as a carrier for the product maltose, which helps in transport of maltose to feed phase from internal aqueous phase. The residual activity of β-amylase after the five-reaction cycle was found to decrease to ∼70%, which indicated possibility to recycle the components of the emulsion and enzyme. The pH and temperature of the encapsulated enzyme were found to be optimum at 5.5 and 60 °C, respectively. The novelty of the present work lies in the development of Enzyme Emulsion Liquid Membranes (EELM) bioreactor for the hydrolysis of starch into maltose mediated by encapsulated β-amylase. The attempt has been made for the first time for the successful encapsulation of β-amylase into EELM. The best results gave the highest residual enzyme activity (94.1%) and maltose production (29.13 mg/mL).