Maximizing the direct recovery and stabilization of cellulolytic enzymes from Trichoderma harzanium BPGF1 fermented broth using carboxymethyl inulin nanoparticles

Abstract

The carboxymethylated inulin (CMI) nanoparticles prepared by the salt out method was demonstrated to harvest cellulolytic enzymes (Ez) directly from the clarified fermented broth of Trichoderma harzanium BPGF1. The formation of CMI nanoparticles and entrapment of Ez in CMI was confirmed by scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. A factorial design was developed to maximize enzymes recovery directly from the fermented broth. A maximum of 71.68 ± 8.61% cellulolytic enzymes was recovered using 20 mg/L inulin, 2 M sodium chloroacetate at 80 °C for 2 h. The resultant CMIEz nanohybrid displayed excellent activity in broad pH and temperature. Moreover, CMIEz was reusable for >30 cycles without losing efficiency. The real-time application of CMIEz was demonstrated by hydrolyzing acid pretreated corncob. High-pressure liquid chromatography revealed that the hydrolyzed corncob contained cellobiose, glucose, galactose, xylose, mannose, and arabinose. The results highlight that carbohydrate nanoparticles was useful in engulfing enzymes directly from the fermentation broth.

Keywords: Carboxymethylated inulin; Enzyme entrapment; Factorial design; Filamentous fungi; Nanohybrid; Reusable.