Figure 2.

Characterisation of alginate-entrapped E. coli [MrαGlu-pET28b(+)] biocatalyst. (a) Hydrolytic activity of soluble (black bars) and immobilized (grey bars) biocatalyst after 24 h incubation at different temperatures (pH 7.0) are shown. (b) Isomelezitose production using immobilized E. coli [MrαGlu-pET28b(+)] cells from 500 g/L sucrose. Reactions were followed for 54 h and different times aliquots were withdrawn and analysed by high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC–PAD). (c) Operational stability of immobilized biocatalyst in transglucosylation reaction cycles of 24–26 h each. Reaction conditions: ~43 mg of alginate-entrapped cells (~2 U), 500 g/L sucrose and 30 °C. In all cases, the results shown corresponded to three independent measurements with the standard deviation.