Synergistic hydrolysis of lignocellulosic biomass using co-immobilization of tri-enzymes on chitosan-magnetite nanoparticle beads.

Abstract

This paper presents the co-immobilization of three enzymes-laccase, cellulase, and xylanase-on chitosan-magnetite nanoparticle beads, with process parameters optimized using response surface methodology on glutaraldehyde-activated chitosan-magnetite beads. The optimization achieved an impressive immobilization yield of 95.25%. Following immobilization on chitosan-magnetite beads (CMBs), the kinetic properties (Km and Vmax), as well as the optimal pH and temperature, were significantly enhanced. The immobilized LCX demonstrated excellent reusability, maintaining 51% of its initial activity after five consecutive cycles, and could be easily recovered using an external magnet. Maximum digestibility of cellulose (% Dc), hemicellulose (% DH), and lignin (% DL) was observed when 10 g of pretreated wheat bran was treated with 20 LCX-loaded CMBs at 40 °C for 60 minutes. The digestibility values for cellulose, hemicellulose, and lignin were 42.10 ± 1.85%, 52.30 ± 2.05%, and 18.12 ± 0.96%, respectively, using immobilized LCX-CMBs-1.0 to 1.5 times higher than those obtained with free enzymes. Additionally, the yield of reducing sugars was 62.17% for immobilized LCX compared to 46.06% for free LCX. The immobilization on CMBs offers an easily removable and cost-effective solution for various industrial applications.