Thermostable endoglucanases in the liquefaction of hydrothermally pretreated wheat straw

N. Szijártó (Corresponding Author), E. Horan, J. Zhang, T. Puranen, Matti Siika-aho, Liisa Viikari

Research output: Contribution to journalArticleScientificpeer-review

41 Citations (Scopus)

Abstract

Background: Thermostable enzymes have several benefits in lignocellulose processing. In particular, they potentially allow the use of increased substrate concentrations (because the substrate viscosity decreases as the temperature increases), resulting in improved product yields and reduced capital and processing costs. A short pre-hydrolysis step at an elevated temperature using thermostable enzymes aimed at rapid liquefaction of the feedstock is seen as an attractive way to overcome the technical problems (such as poor mixing and mass transfer properties) connected with high initial solid loadings in the lignocellulose to ethanol process.

Results: The capability of novel thermostable enzymes to reduce the viscosity of high-solid biomass suspensions using a real-time viscometric measurement method was investigated. Heterologously expressed enzymes from various thermophilic organisms were compared for their ability to liquefy the lignocellulosic substrate, hydrothermally pretreated wheat straw. Once the best enzymes were identified, the optimal temperatures for these enzymes to decrease substrate viscosity were compared. The combined hydrolytic properties of the thermostable preparations were tested in hydrolysis experiments. The studied mixtures were primarily designed to have good liquefaction potential, and therefore contained an enhanced proportion of the key liquefying enzyme, EGII/Cel5A.

Conclusions: Endoglucanases were shown to have a superior ability to rapidly reduce the viscosity of the 15% (w/w; dry matter) hydrothermally pretreated wheat straw. Based on temperature profiling studies, Thermoascus aurantiacus EGII/Cel5A was the most promising enzyme for biomass liquefaction. Even though they were not optimized for saccharification, many of the thermostable enzyme mixtures had superior hydrolytic properties compared with the commercial reference enzymes at 55°C.
Original languageEnglish
JournalBiotechnology for Biofuels
Volume4
Issue number2
DOIs
Publication statusPublished - 2011
MoE publication typeA1 Journal article-refereed

Fingerprint

Cellulase
Straw
Liquefaction
liquefaction
straw
Triticum
Enzymes
wheat
enzyme
Viscosity
viscosity
substrate
Temperature
Substrates
Biomass
Thermoascus
hydrolysis
Hydrolysis
temperature
Saccharification

Keywords

  • wheat
  • wheat straw
  • endoglucanase

Cite this

Szijártó, N. ; Horan, E. ; Zhang, J. ; Puranen, T. ; Siika-aho, Matti ; Viikari, Liisa. / Thermostable endoglucanases in the liquefaction of hydrothermally pretreated wheat straw. In: Biotechnology for Biofuels. 2011 ; Vol. 4, No. 2.
@article{f7eeafb2bbc34b5ca48948691d162573,
title = "Thermostable endoglucanases in the liquefaction of hydrothermally pretreated wheat straw",
abstract = "Background: Thermostable enzymes have several benefits in lignocellulose processing. In particular, they potentially allow the use of increased substrate concentrations (because the substrate viscosity decreases as the temperature increases), resulting in improved product yields and reduced capital and processing costs. A short pre-hydrolysis step at an elevated temperature using thermostable enzymes aimed at rapid liquefaction of the feedstock is seen as an attractive way to overcome the technical problems (such as poor mixing and mass transfer properties) connected with high initial solid loadings in the lignocellulose to ethanol process.Results: The capability of novel thermostable enzymes to reduce the viscosity of high-solid biomass suspensions using a real-time viscometric measurement method was investigated. Heterologously expressed enzymes from various thermophilic organisms were compared for their ability to liquefy the lignocellulosic substrate, hydrothermally pretreated wheat straw. Once the best enzymes were identified, the optimal temperatures for these enzymes to decrease substrate viscosity were compared. The combined hydrolytic properties of the thermostable preparations were tested in hydrolysis experiments. The studied mixtures were primarily designed to have good liquefaction potential, and therefore contained an enhanced proportion of the key liquefying enzyme, EGII/Cel5A.Conclusions: Endoglucanases were shown to have a superior ability to rapidly reduce the viscosity of the 15{\%} (w/w; dry matter) hydrothermally pretreated wheat straw. Based on temperature profiling studies, Thermoascus aurantiacus EGII/Cel5A was the most promising enzyme for biomass liquefaction. Even though they were not optimized for saccharification, many of the thermostable enzyme mixtures had superior hydrolytic properties compared with the commercial reference enzymes at 55°C.",
keywords = "wheat, wheat straw, endoglucanase",
author = "N. Szij{\'a}rt{\'o} and E. Horan and J. Zhang and T. Puranen and Matti Siika-aho and Liisa Viikari",
year = "2011",
doi = "10.1186/1754-6834-4-2",
language = "English",
volume = "4",
journal = "Biotechnology for Biofuels",
issn = "1754-6834",
number = "2",

}

Thermostable endoglucanases in the liquefaction of hydrothermally pretreated wheat straw. / Szijártó, N. (Corresponding Author); Horan, E.; Zhang, J.; Puranen, T.; Siika-aho, Matti; Viikari, Liisa.

In: Biotechnology for Biofuels, Vol. 4, No. 2, 2011.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Thermostable endoglucanases in the liquefaction of hydrothermally pretreated wheat straw

AU - Szijártó, N.

AU - Horan, E.

AU - Zhang, J.

AU - Puranen, T.

AU - Siika-aho, Matti

AU - Viikari, Liisa

PY - 2011

Y1 - 2011

N2 - Background: Thermostable enzymes have several benefits in lignocellulose processing. In particular, they potentially allow the use of increased substrate concentrations (because the substrate viscosity decreases as the temperature increases), resulting in improved product yields and reduced capital and processing costs. A short pre-hydrolysis step at an elevated temperature using thermostable enzymes aimed at rapid liquefaction of the feedstock is seen as an attractive way to overcome the technical problems (such as poor mixing and mass transfer properties) connected with high initial solid loadings in the lignocellulose to ethanol process.Results: The capability of novel thermostable enzymes to reduce the viscosity of high-solid biomass suspensions using a real-time viscometric measurement method was investigated. Heterologously expressed enzymes from various thermophilic organisms were compared for their ability to liquefy the lignocellulosic substrate, hydrothermally pretreated wheat straw. Once the best enzymes were identified, the optimal temperatures for these enzymes to decrease substrate viscosity were compared. The combined hydrolytic properties of the thermostable preparations were tested in hydrolysis experiments. The studied mixtures were primarily designed to have good liquefaction potential, and therefore contained an enhanced proportion of the key liquefying enzyme, EGII/Cel5A.Conclusions: Endoglucanases were shown to have a superior ability to rapidly reduce the viscosity of the 15% (w/w; dry matter) hydrothermally pretreated wheat straw. Based on temperature profiling studies, Thermoascus aurantiacus EGII/Cel5A was the most promising enzyme for biomass liquefaction. Even though they were not optimized for saccharification, many of the thermostable enzyme mixtures had superior hydrolytic properties compared with the commercial reference enzymes at 55°C.

AB - Background: Thermostable enzymes have several benefits in lignocellulose processing. In particular, they potentially allow the use of increased substrate concentrations (because the substrate viscosity decreases as the temperature increases), resulting in improved product yields and reduced capital and processing costs. A short pre-hydrolysis step at an elevated temperature using thermostable enzymes aimed at rapid liquefaction of the feedstock is seen as an attractive way to overcome the technical problems (such as poor mixing and mass transfer properties) connected with high initial solid loadings in the lignocellulose to ethanol process.Results: The capability of novel thermostable enzymes to reduce the viscosity of high-solid biomass suspensions using a real-time viscometric measurement method was investigated. Heterologously expressed enzymes from various thermophilic organisms were compared for their ability to liquefy the lignocellulosic substrate, hydrothermally pretreated wheat straw. Once the best enzymes were identified, the optimal temperatures for these enzymes to decrease substrate viscosity were compared. The combined hydrolytic properties of the thermostable preparations were tested in hydrolysis experiments. The studied mixtures were primarily designed to have good liquefaction potential, and therefore contained an enhanced proportion of the key liquefying enzyme, EGII/Cel5A.Conclusions: Endoglucanases were shown to have a superior ability to rapidly reduce the viscosity of the 15% (w/w; dry matter) hydrothermally pretreated wheat straw. Based on temperature profiling studies, Thermoascus aurantiacus EGII/Cel5A was the most promising enzyme for biomass liquefaction. Even though they were not optimized for saccharification, many of the thermostable enzyme mixtures had superior hydrolytic properties compared with the commercial reference enzymes at 55°C.

KW - wheat

KW - wheat straw

KW - endoglucanase

U2 - 10.1186/1754-6834-4-2

DO - 10.1186/1754-6834-4-2

M3 - Article

VL - 4

JO - Biotechnology for Biofuels

JF - Biotechnology for Biofuels

SN - 1754-6834

IS - 2

ER -