Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass

Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass

Bibliographic Details
Main Author: Samayam, Indira Priya
Language:English
Published: University of Toledo / OhioLINK 2011
Subjects:
Alternative Energy
ionic liquid
cellulose II
saccharification
Spezyme CP
Pichia stipitis
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=toledo1313700629
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-toledo13137006292021-08-03T06:08:03Z Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass Samayam, Indira Priya Alternative Energy ionic liquid cellulose II saccharification Spezyme CP Pichia stipitis The goal of this dissertation research is to gain a more fundamental understanding of the impact of ionic liquid (IL) pretreatment of lignocellulosic biomass in production of ethanol and other chemicals through a sugar platform and biochemical conversion of polysaccharides to monomeric sugars. Recalcitrance of cellulose hydrolysis is a primary roadblock for efficient enzymatic conversion of lignocellulosic biomass to monomeric sugars that are fermented to ethanol or other products. The structure of lignocellulosic biomass is rendered amenable to enzymatic saccharification upon IL pretreatment. Changes in the structure of cellulose in relation to the biomass digestibility with varying ionic liquid (IL) pretreatment were examined. Conversion of native cellulose I to amorphous cellulose or cellulose II improved the susceptibility of cellulose to enzymatic hydrolysis.The performance of commercial enzyme mixtures were evaluated through saccharification of IL pretreated biomass substrates (poplar and switchgrass) at low biomass slurry concentrations. Poplar and switchgrass hydrolysis with commercial cellulase, Spezyme CP, and Multifect Xylanase showed synergism between the two enzymes. However, switchgrass hydrolysis was less complete than that of poplar, likely due to differences in hemicellulose structural features. Hydrolysis of polysaccharides in lignocellulose at high biomass slurry concentrations is essential in economical fermentation of hydrolyzates to ethanol and other products. Commercial enzyme mixtures were varied for simultaneous or sequential hydrolysis and fermentation of pentose and hexose sugars with Pichia stipitis for IL treated poplar. In sequential hydrolysis of poplar at modest enzyme loadings of 9 mg/g xylan Multifect Xylanase, 1.8 mg/ g xylan SXA (ß-xylosidase) at 50°C in the first step and 10 FPU/g glucan Spezyme CP, and 40 CBU/g glucan Novozyme 188 at 25°C in the second step, the yields of glucose and xylose at 15% (w/v) solid loadings were 61% and 83%, respectively. The incomplete hydrolysis may be due to the accumulation of cellobiose and low activity of enzymes at 25°C. Further increase in Novozyme 188 loadings or hydrolysis may improve hydrolysis yields. A maximum of 66% theoretical ethanol yield based on initial sugar analysis of poplar was expected from these hydrolyzates if all the released sugars were fermented to ethanol. In sequential hydrolysis and fermentation with P. stipitis, 56% theoretical ethanol yields based on the initial sugar composition of poplar respectively was achieved. 2011 English text University of Toledo / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=toledo1313700629 http://rave.ohiolink.edu/etdc/view?acc_num=toledo1313700629 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Alternative Energy
ionic liquid
cellulose II
saccharification
Spezyme CP
Pichia stipitis
spellingShingle Alternative Energy
ionic liquid
cellulose II
saccharification
Spezyme CP
Pichia stipitis
Samayam, Indira Priya
Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass
author Samayam, Indira Priya
author_facet Samayam, Indira Priya
author_sort Samayam, Indira Priya
title Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass
title_short Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass
title_full Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass
title_fullStr Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass
title_full_unstemmed Characterization and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass
title_sort characterization and saccharification of ionic liquid pretreated lignocellulosic biomass
publisher University of Toledo / OhioLINK
publishDate 2011
url http://rave.ohiolink.edu/etdc/view?acc_num=toledo1313700629
work_keys_str_mv AT samayamindirapriya characterizationandsaccharificationofionicliquidpretreatedlignocellulosicbiomass
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