Comparison of thermostable xylanase production by Escherichia coli immobilised onto different nanoparticles

Abstract

Immobilisation process can be applied for both whole cells and enzymes to optimise the operational performance system for industrial applications. A successful immobilisation process leads to the development of economically and ecologically available biocatalyst such as xylanase. However cell lysis becomes one of the biggest problems in the enzyme excretion when E. coli is used as a host. In this study, the effects of different nanoparticles on xylanase excretion and cell lysis of immobilized E. coli were examined. For protein expression, the cells were cultured in various immobilized matrices on graphene oxide treated, graphene oxide untreated, carbon nanotube treated and carbon nanotube untreated with 100 mg/mL IPTG concentrations at 30 °C temperature and 200 rpm agitation rate for 24 h. The immobilised cells demonstrated a 7 % increase in xylanase excretion and a 39 % reduction of cell lysis compared with free cells using untreated graphene oxide. Consequently, the immobilisation of E. coli using nanoparticles was verified to increase xylanase excretion and cell stability.