Optimization of κ-Selenocarrageenase Production by Pseudoalteromonas sp.X13 and Its Immobilization

Abstract

Abstract The bioenzymatic production of selenium oligosaccharides addresses the problems resulted from high molecular weight and poor water solubility of κ-selenocarrageenan, and lays a foundation for its application as adjuvant drugs for cancer treatment, and food additive. κ-Selenocarrageenase extracted from Pseudoalteromonas sp. Xi13 can degrade κ-selenocarrageenan to selenium oligosaccharides. The maximum optimized κ-selenocarrageenase activity using RSM was increased by 1.4 times, reached 8.416 U/ mL, under the optimum fermentation conditions: 1.6% κ-selenocarrageenan, 3.7 mmol/L Ca2+, and 33℃. The immobilized κ-selenocarrageenase exhibits good stability, 58.28% of enzyme activity was remained after reusing for four times. Selenium content of κ-selenocarrageenan oligosaccharide degraded by immobilized κ-selenocarrageenase was 47.06 µg/g, 8.3% higher than that degraded by the lyophilized enzyme. The results indicate that immobilized κ-selenocarrageenase is suitable for industrial applications and has commercial potential.