Expression of chitinase gene in BL21 pET system and investigating the biocatalystic performance of chitinase-loaded AlgSep nanocomposite beads

Chitin, a polysaccharide, is abundant in nature and this substrate can be easily hydrolyzed by chitinase. Pharmaceutical and industrial applications of chitinase are considerably noteworthy, therefore in this study, high scale production of Chit36 enzyme was targeted using the E. coli pET expression system. The purified Chit36 enzyme was immobilized in Ca2+-cross linked alginate/sepiolite (AlgSep) nanocomposite beads for improving the catalytic activity and stability of Chit36 enzyme during the biocatalytic process. Immobilized enzymes require optimal conditions different from soluble enzymes. The AlgSep nanocomposite can save spatial structure and activity of the enzyme which is critical for enzyme immobilization. The catalytic activity and specific activity of the Chit36 entrapped in alginate nanocomposite beads were evaluated. Results showed that the activity of immobilized Chit36 in Ca-Alginate sepiolite composites beads (3.10 ± 0.63 U/g gel) was higher than that of immobilized Chit36 in Ca-alginate beads (3.95 ± 0.40 U/g gel). Also, the specific activity of Chit36 in AlgSep nanocomposite beads (22.9 ± 1.521 U/mg protein) was higher than the immobilized Chit36 in sepiolite-free alginate beads (8.52 ± 0.758 U/mg protein). The promising results obtained from this study would have beneficial pharmaceutical and industrial applications.