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Does sugar inhibition explain mixing effects in enzymatic hydrolysis of lignocellulose?

Kadic, Adnan LU and Lidén, Gunnar LU (2017) In Journal of Chemical Technology and Biotechnology 92(4). p.868-873
Abstract

BACKGROUND: Enzymatic hydrolysis of lignocellulose is associated with mixing issues, which are likely to affect process performance. The aim of this study was to investigate how viscosity and sugar inhibition influence the mixing-dependence in hydrolysis of steam-pretreated spruce. RESULTS: The effect of agitation on low-viscosity, low-solid hydrolysis (5% water insoluble solid (WIS)) was marginal, as the conversion after 72 h decreased by 9% when decreasing the agitation rate from 600 to 100 rpm. However, when the viscosity at 5% WIS was increased by Xanthan addition, the effect of agitation was greater, and conversion decreased by 21% when decreasing agitation from 600 to 100 rpm. For high-viscosity, high-solid hydrolysis (16% WIS),... (More)

BACKGROUND: Enzymatic hydrolysis of lignocellulose is associated with mixing issues, which are likely to affect process performance. The aim of this study was to investigate how viscosity and sugar inhibition influence the mixing-dependence in hydrolysis of steam-pretreated spruce. RESULTS: The effect of agitation on low-viscosity, low-solid hydrolysis (5% water insoluble solid (WIS)) was marginal, as the conversion after 72 h decreased by 9% when decreasing the agitation rate from 600 to 100 rpm. However, when the viscosity at 5% WIS was increased by Xanthan addition, the effect of agitation was greater, and conversion decreased by 21% when decreasing agitation from 600 to 100 rpm. For high-viscosity, high-solid hydrolysis (16% WIS), the conversion decreased by 54% when decreasing the agitation from 600 to 100 rpm. However, when the product concentration was kept low by simultaneous saccharification and fermentation (SSF), the effect of agitation was weaker, and conversion decreased by only 14%. CONCLUSION: The results of this study strongly suggest that poor mixing in viscous lignocellulose hydrolysis causes local product accumulation, leading to increased inhibition and decreased hydrolysis rates. Decreasing the glucose and cellobiose concentration removes the mixing-dependence, highlighting SSF as an attractive option for large-scale hydrolysis and fermentation of steam-pretreated softwood. © 2016 Society of Chemical Industry.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
biomass, enzymes, mass transfer, mixing, rheology, wood
in
Journal of Chemical Technology and Biotechnology
volume
92
issue
4
pages
6 pages
publisher
Wiley-Blackwell
external identifiers
  • scopus:84992643480
ISSN
0268-2575
DOI
10.1002/jctb.5071
language
English
LU publication?
yes
id
23fe1ace-c11d-46b5-bab3-bb858d96c9d0
date added to LUP
2017-04-25 09:24:11
date last changed
2017-04-25 09:24:11
@article{23fe1ace-c11d-46b5-bab3-bb858d96c9d0,
  abstract     = {<p>BACKGROUND: Enzymatic hydrolysis of lignocellulose is associated with mixing issues, which are likely to affect process performance. The aim of this study was to investigate how viscosity and sugar inhibition influence the mixing-dependence in hydrolysis of steam-pretreated spruce. RESULTS: The effect of agitation on low-viscosity, low-solid hydrolysis (5% water insoluble solid (WIS)) was marginal, as the conversion after 72 h decreased by 9% when decreasing the agitation rate from 600 to 100 rpm. However, when the viscosity at 5% WIS was increased by Xanthan addition, the effect of agitation was greater, and conversion decreased by 21% when decreasing agitation from 600 to 100 rpm. For high-viscosity, high-solid hydrolysis (16% WIS), the conversion decreased by 54% when decreasing the agitation from 600 to 100 rpm. However, when the product concentration was kept low by simultaneous saccharification and fermentation (SSF), the effect of agitation was weaker, and conversion decreased by only 14%. CONCLUSION: The results of this study strongly suggest that poor mixing in viscous lignocellulose hydrolysis causes local product accumulation, leading to increased inhibition and decreased hydrolysis rates. Decreasing the glucose and cellobiose concentration removes the mixing-dependence, highlighting SSF as an attractive option for large-scale hydrolysis and fermentation of steam-pretreated softwood. © 2016 Society of Chemical Industry.</p>},
  author       = {Kadic, Adnan and Lidén, Gunnar},
  issn         = {0268-2575},
  keyword      = {biomass,enzymes,mass transfer,mixing,rheology,wood},
  language     = {eng},
  month        = {04},
  number       = {4},
  pages        = {868--873},
  publisher    = {Wiley-Blackwell},
  series       = {Journal of Chemical Technology and Biotechnology},
  title        = {Does sugar inhibition explain mixing effects in enzymatic hydrolysis of lignocellulose?},
  url          = {http://dx.doi.org/10.1002/jctb.5071},
  volume       = {92},
  year         = {2017},
}