Facile immobilization of Pseudomonas fluorescens lipase on polyaniline nanofibers (PANFs-PFL): A route to develop robust nanobiocatalyst.

Herein, we demonstrate the immobilization of Pseudomonas fluorescens lipase (PFL) on polyaniline nanofibers (PANFs) via physical adsorption. Polyaniline nanofibers (PANFs) were synthesized by the oxidative polymerization of aniline. The developed robust nanobiocatalyst (PANFs-PFL) exhibited eight times higher activity than free PFL. In addition, immobilization of lipase on PANFs imparted operational stability of the nanobioconjugate. The various reaction parameters for immobilization (viz. reaction time, pH, stirring rate and enzyme-support ratio) were optimized using statistical design in terms of lipase activity and loading. Furthermore, facile separation, enhanced reusability (upto 6 cycles) and thermostability (upto 75 °C) were additional advantages of the nanobioconjugate. The catalytic prowess of nanobioconjugate was examined in the kinetic resolution of (RS)-N-(4-(3-chloro-2-hydroxypropoxy)phenyl)acetamide and (RS)-1-(1-naphthyl) ethanol in comparison to free PFL. PANFs-PFL demonstrated 49.9% and 48.1% conversion for (RS)-N-(4-(3-chloro-2-hydroxypropoxy)phenyl)acetamide and (RS)-1-(1-naphthyl) ethanol, respectively which signified its importance as a nanobiocatalyst.