Immobilization of thermophilic recombinant esterase enzyme by entrapment in coated Ca-alginate beads

Abstract

Recently, industrial enzymes produced by micro-organisms are being utilized widely, especially from thermophilic ones due to their ability to withstand intense heat. Esterase enzymes from thermophilic micro-organisms are special interest in a variety of biotechnological applications because of their many useful properties. Due to potential use as biocatalysts in variety of biotechnological applications, esterase enzyme isolated from Balçova (Agamemnon) geothermal site were aimed to be immobilized via a costeffective protocol, in order to be re-used over very long periods of time. Previously, the gene encoding thermophilic esterase from the thermal environmental samples, isolated from Balçova (Agamemnon) geothermal site, was cloned and respective protein was expressed in Escherichia coli in our group. In this study using that recombinant esterase enzyme, expression, purification and immobilization studies were carried out. The esterase enzyme was immobilized in the Ca-alginate beads which were coated with silica and the effects of the temperature and pH on the immobilized enzyme was determined and diameter of the beads, reuse and surface of the beads were analyzed. Immobilization yield for coated beads was determined as 71.27% and compared with non-coated ones which were 45.80%. Analysis of surface morphologies of beads was compared with Scanning Electron Microscope.