A robust nanobiocatalyst based on high performance lipase immobilized to novel synthesised poly(o-toluidine) functionalized magnetic nanocomposite: Sterling stability and application

Herein, as a promising support, a magnetic enzyme nanoformulation have been designed and fabricated by a poly-o-toluidine modification approach. Owing to the magnetic nature and the existence of amine functionalized groups, the as-synthesised poly(o-toluidine) functionalized magnetic nanocomposite (Fe3O4@POT) was employed as potential support for Candida rugosa lipase (CRL) immobilization to explore its application in fruit flavour esters synthesis. The morphology and structure of the Fe3O4@POT NC were examined through various analytical tools. Hydrolytic activity assays disclose that immobilized lipase demonstrated an activity yield of 120%. It is worth mentioning that CRL#Fe3O4@POT showed superior resistance to extremes of temperature and pH and different organic solvents in contrast to free CRL. The magnetic behaviour of the as-synthesised NC was affirmed by alternating gradient magnetometer analysis. It was found to own facile immobilization process, enhanced catalytic performance for the immobilized form which may be stretched to the immobilization of various vital industrial enzymes. Moreover, it retained improved recycling performance. After 10 cycles of repetitive uses, it still possessed around 90% of its initial activity for the hydrolytic reaction, since the enzyme magnetic nanoconjugate was effortlessly obtained using a magnet from the reaction system. The formulated nanobiocatalyst was selected for the esterification reaction to synthesize the fruit flavour esters, ethyl acetoacetate and ethyl valerate. The immobilized lipase successfully synthesised flavour compounds in aqueous and n-hexane media having significant higher ester yields compared to free enzyme. The present work successfully combines an industrially prominent biocatalyst, CRL, and a novel magnetic nanocarrier, Fe3O4@POT, into an immobilized nanoformulation with upgraded catalytic properties which has excellent potential for practical industrial implications.