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Immobilization with Ca–Alg@gelatin hydrogel beads enhances the activity and stability of recombinant thermoalkalophilic lipase

Yildiz Dalginli Kezban, Atakisi Onur

Chemical and Process Engineering : New Frontiers

2023

Vol. 44, nr 1

art. no. e2

This study aims at the immobilization and characterization of thermoalkalophilic lipases produced recombinantly from Bacillus thermocatenulatus BTL2 and Bacillus pumilus MBB03. For this purpose, immobilization of the produced enzymes in calcium-alginate@gelatin (Ca–Alg@gelatin) hydrogel beads, immobilization optimization and characterization measurements of the immobilized-enzyme hydrogels were conducted. Optimum temperature and pH values were determined for B. thermocatenulatus and B. pumilus MBB03 immobilized-enzyme hydrogels (60–70 °C, 55 °C and pH 9.5, pH 8.5). Thermal stability was determined between 65 °C and 60 °C of B. thermocatenulatus and B. pumilus MBB03 immobilized enzymes, respectively. The pH stability was determined between pH 7.0–11.0 at +4°C and pH 8.0–10.0 at +4 °C, respectively. In conclusion, the entrapment technique provided controlled production of small diameter hydrogel beads (~ 0:19 and ~ 0:29) with negligible loss of enzyme. These beads retained high lipase activity at high pH and temperature. The activity of Ca–Alg@gelatin-immobilized lipase remained relatively stable for up to three cycles and then markedly decreased. With this enzyme immobilization, it may have a potential for use in esterification and transesterification reactions carried out in organic solvent environments. We can conclude that it is one of the most promising techniques for highly efficient and economically competent biotechnological processes in the field of biotransformation, diagnostics, pharmaceutical, food and detergent industries.

A simple synthetic route for the preparation of a reversed-phase stationary phase based on monosized-porous hydrogel beads and its chromatographic use for separation of small molecules

Çelebi B.

Acta Chromatographica

2017

Vol. 29, no. 2

143--159

New polyacrylate-based monosized-porous polymer beads were proposed as a stationary phase for the separation of polar compounds by microbore reversed-phase chromatography. For this purpose, monosized-porous poly(glycerol dimethacrylate-co-glycerol-1,3-diglycerolate diacrylate), poly(GDMA-co-GDGDA), beads with hydroxyl functionality were synthesized by a modified seeded polymerization. The selected octadecylating agent, stearoyl chloride (SC), was covalently attached onto the hydrophilic beads via a direct, single stage reaction with a simple synthetic route. SC attached-poly( GDMA-co-GDGDA) beads were slurry-packed into the microbore columns and used as separation medium microbore reversed-phase chromatography. The stationary phase was used for separation of alkylbenzenes and polar analytes by micro reversed-phase chromatography, using mobile phases with low acetonitrile content. Theoretical plate number (TPN) values up to 12,000 plates m−1 and 10,000 plates m−1 for alkylbenzenes and polar analytes, respectively, were achieved. The results also showed that poly(GDMA-co-GDGDA) hydrogel beads are a promising starting material for a number of chromatographic applications like reversed-phase (RP) chromatography, hydrophilic interaction chromatography (HILIC), ion-exchange chromatography (IEC), and affinity chromatography with a single-stage surface modification.