Immobilization of thermoalkalophilic recombinant esterase enzyme by entrapment in silicate coated Ca-alginate beads and its hydrolytic properties

Abstract

a b s t r a c tThermoalkalophilic esterase enzyme from Balç ova (Agamemnon) geothermal site were aimed to be immobilized effectively via a simple and cost-effective protocol in silicate coated Calcium alginate (Caalginate) beads by entrapment. The optimal immobilization conditions of enzyme in Ca-alginate beads were investigated and obtained with 2% alginate using 0.5 mg/ml enzyme and 0.7 M CaCl 2 solution. In order to prevent enzyme from leaking out of the gel beads, Ca-alginate beads were then coated with silicate. Enzyme loading efficiency and immobilization yield for silicate coated beads was determined as 98.1% and 71.27%, respectively and compared with non-coated ones which were 68.5% and 45.80%, respectively. Surface morphologies, structure and elemental analysis of both silicate coated and noncoated alginate beads were also compared using Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscope (SEM) equipped with Energy-dispersive X-ray spectroscopy (EDX). Moreover, silicate coated alginate beads enhanced reusability of esterase in continuous processes compared to non-coated beads. The hydrolytic properties of free and immobilized enzyme in terms of storage and thermal stability as well as the effects of the temperature and pH were determined. It was observed that operational, thermal and storage stabilities of the esterase were increased with immobilization.

Adsorption Kinetics of Cobalt (II) Ions onto Alginate Beads from Aqueous Solutions

“…Because of alginate's negative charge, it is viscous and can be forged into a gel. Using this property, alginate gel beads can be formed by encapsulating calcium ions, which have a very low toxicity, in alginate beads [5]. The adsorptive properties of this material reside on the presence of carboxylic acid and hydroxyl functional groups that have a high affinity towards heavy metals and other polar compounds.…”

Oyster mushroom’s lipase enzyme entrapment on calcium alginate as biocatalyst in the synthesis of lauryl diethanolamide

“…Calcium alginate formed is not soluble in water. That's because the calcium to form a bi-cations Ca 2+ and forming a chelate with oxygen guluronic [3]. The initial steps to immobilize it entrapment reaction was mixed the enzyme into each Na-alginate solution of 1%, 2%, 3%, and 4% in comparison with the lipase alginate is 2: 3.…”

“…One way to overcome this drawback is to apply the enzyme immobilization techniques to be used. Enzyme immobilization aims to improve the stability and productivity of these enzymes so that the lipase can be reused [3][4][5].…”

Characterization of Waste Clay from Palm Oil Mill Effluent and Enzyme Immobilization Study for Cassava Saccharification Process

“…The increase in loading efficiency of enzymes with high clay concentrations may be due to the formation of stronger and tighter beads; however, the immobilization yield slightly decreased as the clay concentration increased. The decrease in activity of the encapsulated enzymes in the clay beads is attributed to the diffusion limitation of the substrate to react with the enzymes (Gülay and Şanlı-Mohamed 2012). The enzymes encapsulated alginate-clay beads characterization have been thoroughly studied and published elsewhere (Edama et al 2014b).…”

“…The decrease in the enzyme activities may be due to enzyme leakage resulting from the soft surface of the alginate gel. Other reasons for the leakage may be damage to the beads during the repeated use and washing steps at the end of each cycle (Gülay and Şanlı-Mohamed 2012). …”