Purification and immobilization of exo-polygalacturonase using nanomagnetic beads

The novel kappa carrageenan-chitosan nanomagnetics (CCMNs) and chitosan-pectin nanomagnetics (CPMNs) were synthesized via situ co-precipitation and characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and X-ray diffraction (XRD) methods. The highest Piriformospora indica exo-polygalacturonase (exo-PG) specific activity (32.48 U/mg) was monitored on pectin-containing YPG medium after 4 days of incubation. Then, exo-PG were purified and immobilized by CCMNs and CPMNs. The enzyme attached to the nanomagnetic carriers by physical adsorption. The purified Exo-PG had an apparent molecular weight of 60 kDa which illustrated maximal activity at pH 6.0 and 40 degrees C. The specific activity of the purified enzyme by CCMNs and CPMNs was determined 479 U/mg and 204 U/mg, respectively. Exo-PG immobilized on CPMNs had a recovered activity of 71.11 % with an immobilization yield of 89.15 %. Furthermore, CCMNs-PG exhibited recovered activity of 65.96 % with an immobilization yield of 63.85 %. Moreover, the immobilized Exo-PG on CPMNs and CCMNs beads retained 72 % and 60 % of respectively their initial activity after 6 successive cycles. Overall, findings of this investigation might open new insights to apply nanomagnetics for exo-PG purification and immobilization in food industries.

Automated summary

The kappa carrageenan-chitosan nanomagnetics (CCMNs) and chitosan-pectin nanomagnetics (CPMNs) were synthesized and characterized. The exo-polygalacturonase (exo-PG) was purified and immobilized on CCMNs and CPMNs by physical adsorption. The immobilized Exo-PG on CPMNs and CCMNs beads showed retained activity after multiple cycles, indicating their potential application in food industries.