ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Immobilization of cellulase on magnetized multiwall carbon nanotubes (m-MWCNTs) synthesized via eco-friendly (water-based) method

Hasnol Azahari Natasha Yasmin, Sandrasekaran Naresh, Balakrishnan Kunasundari, and Siew Hoong Shuit

Fakulti Teknologi Kejuruteraan Kimia, Universiti Malaysia Perlis, Arau, Perlis, Malaysia

E-mail: kunasundari@unimap.edu.my

Received: 22 April 2021  Accepted: 12 September 2021

Abstract:

The interest in using magnetic nanoparticle (MNPs) as a carrier for immobilization is overwhelming due to high surface area and lightweight properties. However, the conventional synthesis of MNPs required use of high amount of chemicals and is a time-consuming process. Thus, in the present research, magnetized multiwall carbon nanotubes (m-MWCNTs) were successfully synthesized via water-based system using simple steps. The synthesized m-MWCNTs was used as carrier for the immobilization of cellulase. Cellulase was proven to be successfully bounded on m-MWCNTs using Fourier transform infrared spectroscopy that revealed a peak at 580.33 cm⁻¹ indicating Fe–O stretching in parallel with observation of rougher and coarser surface of m-MWCNTs through scanning electron microscope. The total binding efficiency of cellulase to the m-MWCNTs was determined to be 95% at 5 mg/mL of the enzyme concentration. The activity of the immobilized cellulase was evaluated using carboxymethyl cellulose (CMC) as a substrate. Both of free and immobilized cellulase showed optimum working condition at 50 °C and pH 5. Furthermore, the immobilized cellulase was found to be able to retain more than 50% of its initial activity at the fifth cycle of the hydrolysis of CMC and filter paper. A similar activity was recorded with paddy straw at the third cycle of hydrolysis.

Keywords: Cellulase; Immobilization; Carboxymethyl cellulose (CMC); Filter paper; Magnetized multiwall carbon nanotubes (m-MWCNTs); Paddy straw; Recovery

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01874-7

Chemical Papers 76 (1) 453–464 (2022)