Synthesis of p-hydroxyphenylglicine by cell extract from Agrobaterium radiobacter encapsulated in alginate capsules

A crude cell extract from Agrobacterium radiobacter was encapsulated in calcium-alginate capsules for the synthesis of p-hydroxyphenylglicine (p-HPG). The effect of the encapsulation process on the two enzymatic activities involved on the p-HPG synthesis was studied. The encapsulation process was optimised with regard to alginate concentration and ratio extract:alginate. The encapsulation efficiency was around a 60% and the derivatives showed a p-HPG synthesis yield of around a 50%. The optimum temperature was 55 °C and the activation energy (Ea) of the whole process was 4.4 kcal/mol. The biocatalyst could be used six times without any activity loss.