Applied Biochemistry and Biotechnology

, Volume 176, Issue 4, pp 1114–1130

Modeling the Effect of pH and Temperature for Cellulases Immobilized on Enzymogel Nanoparticles

  • Ashani Samaratunga
  • Olena Kudina
  • Nurun Nahar
  • Andrey Zakharchenko
  • Sergiy Minko
  • Andriy Voronov
  • Scott W. Pryor
Article

DOI: 10.1007/s12010-015-1633-z

Cite this article as:
Samaratunga, A., Kudina, O., Nahar, N. et al. Appl Biochem Biotechnol (2015) 176: 1114. doi:10.1007/s12010-015-1633-z

Abstract

Production costs of cellulosic biofuels can be lowered if cellulases are recovered and reused using particulate carriers that can be extracted after biomass hydrolysis. Such enzyme recovery was recently demonstrated using enzymogel nanoparticles with grafted polymer brushes loaded with cellulases. In this work, cellulase (NS50013) and β-glucosidase (Novozyme 188) were immobilized on enzymogels made of poly(acrylic acid) polymer brushes grafted to the surface of silica nanoparticles. Response surface methodology was used to model effects of pH and temperature on hydrolysis and recovery of free and attached enzymes. Hydrolysis yields using both enzymogels and free cellulase and β-glucosidase were highest at the maximum temperature tested, 50 °C. The optimal pH for cellulase enzymogels and free enzyme was 5.0 and 4.4, respectively, while both free β-glucosidase and enzymogels had an optimal pH near 4.4. Highest hydrolysis sugar concentrations with cellulase and β-glucosidase enzymogels were 69 and 53 % of those with free enzymes, respectively. Enzyme recovery using enzymogels decreased with increasing pH, but cellulase recovery remained greater than 88 % throughout the operating range of pH values less than 5.0 and was greater than 95 % at pH values below 4.3. Recovery of β-glucosidase enzymogels was not affected by temperature and had little impact on cellulase recovery.

Keywords

Immobilized enzymes Enzymatic hydrolysis Cellulase Enzyme recovery Response surface methodology Enzymogel 

Abbreviations

PAA

Poly(acrylic acid)

IUPAC

International Union of Pure and Applied Chemistry

RSM

Response surface methodology

ANOVA

Analysis of variance

HPLC

High-performance liquid chromatography

DNS

Dinitrosalicylic acid

BSA

Bovine serum albumin

Supplementary material

12010_2015_1633_MOESM1_ESM.docx (17 kb)
ESM 1(DOCX 16 kb)

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Ashani Samaratunga
    • 1
  • Olena Kudina
    • 2
  • Nurun Nahar
    • 1
  • Andrey Zakharchenko
    • 3
  • Sergiy Minko
    • 3
  • Andriy Voronov
    • 2
  • Scott W. Pryor
    • 1
  1. 1.Department of Agricultural and Biosystems EngineeringNorth Dakota State UniversityFargoUSA
  2. 2.Department of Coatings and Polymeric MaterialsNorth Dakota State UniversityFargoUSA
  3. 3.Nanostructured Materials LaboratoryUniversity of GeorgiaAthensUSA

Personalised recommendations