A comparative study of immobilized lipase produced from Penicillium chrysogenum SNP5 on two different anionic carriers for its pH and thermostability

The present work aimed to increase the thermostability and pH stability of lipase produced from Penicillium chrysogenum SNP5 using different anionic carriers. The immobilized lipase from the fungus on 1.25% sodium alginate beads and 12% polyacrylamide beads retained 37.28 and 59.75% immobilization efficiency, respectively, on 3 mm bead size. Immobilized lipase on calcium alginate and polyacrylamide beads retained 56.16 and 91.11% of its initial activity after 3 use, whereas significant loss in lipase activity was observed after 5 and 7 reuse, respectively. Properties like optimum pH, Km, Vmax and thermostability of immobilized lipase were changed with respect to free lipase. Optimum pH shifted from 7 to 7.5 in calcium alginate and from 7 to 9 in polyacrylamide beads, whereas t1/2 increased from 71 min to 205 min in calcium alginate and from 71 min to 380 min in polyacrylamide beads at 45°C. Km and Vmax values at free state lipase were observed as 0.30 mM and 31.948 μM min mL, whereas after immobilization on calcium alginate and polyacrylamide beads values changed to 0.188 mM and 27.24 μM min mL, and 0.24 mM and 30.96 μmol min mL, respectively. Thus, on immobilization, lipase has shown enhanced thermostability, specificity and working range of pH, which would be more beneficial for its industrial application.