Integrated process for the purification and immobilization of recombinant trehalose synthase for trehalose production

In this study an integrated process for the concomitant purification and immobilization of recombinant Picrophilus torridus trehalose synthase for the synthesis of trehalose was reported. A highly porous crosslinked polystyrene divinylbezene-based metal chelator was used for the purification and immobilization of the poly(His)-tagged enzyme. While the Cu(II)-loaded adsorbent showed the highest protein adsorption capacity, 5.39 ± 0.03 mg protein/g, the Co(II)-loaded adsorbent exhibited the highest specificity for the adsorption of the poly(His)-tagged trehalose synthase, giving a specific activity of 3.98 ± 0.50 U/mg protein, more than fourfold higher than that of the Cu(II)-loaded adsorbent. No significant differences in optimal operation pH, temperature, and thermostability were observed upon immobilization. Under optimal reaction conditions, a trehalose conversion yield of 64.1% was obtained within 6 h. A residual activity of approximately 80% was maintained after 24 cycles in a repeated-batch operation. The decline in residual activity was primarily due to the desorption of the recombinant trehalose synthase. The proposed integrated approach for enzyme purification and immobilization with the metal chelator is promising for the development of industrial processes for trehalose production.