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Bioavailability of Carbohydrate Content in Natural and Transgenic Switchgrasses for the Extreme Thermophile Caldicellulosiruptor bescii

Journal Article · · Applied and Environmental Microbiology
DOI:https://doi.org/10.1128/AEM.00969-17· OSTI ID:1394607
 [1];  [1];  [2];  [1];  [1];  [1];  [1];  [3];  [4];  [5];  [1]
  1. North Carolina State Univ., Raleigh, NC (United States)
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Georgia Inst. of Technology, Atlanta, GA (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Univ. of Georgia, Athens, GA (United States)
ABSTRACT

Improving access to the carbohydrate content of lignocellulose is key to reducing recalcitrance for microbial deconstruction and conversion to fuels and chemicals. Caldicellulosiruptor bescii completely solubilizes naked microcrystalline cellulose, yet this transformation is impeded within the context of the plant cell wall by a network of lignin and hemicellulose. Here, the bioavailability of carbohydrates toC. bescii at 70°C was examined for reduced lignin transgenic switchgrass lines COMT3(+) and MYB Trans, their corresponding parental lines (cultivar Alamo) COMT3(–) and MYB wild type (WT), and the natural variant cultivar Cave-in-Rock (CR). Transgenic modification improved carbohydrate solubilization by C. bescii to 15% (2.3-fold) for MYB and to 36% (1.5-fold) for COMT, comparable to the levels achieved for the natural variant, CR (36%). Carbohydrate solubilization was nearly doubled after two consecutive microbial fermentations compared to one microbial step, but it never exceeded 50% overall. Hydrothermal treatment (180°C) prior to microbial steps improved solubilization 3.7-fold for the most recalcitrant line (MYB WT) and increased carbohydrate recovery to nearly 50% for the least recalcitrant lines [COMT3(+) and CR]. Alternating microbial and hydrothermal steps (T→M→T→M) further increased bioavailability, achieving carbohydrate solubilization ranging from 50% for MYB WT to above 70% for COMT3(+) and CR. Incomplete carbohydrate solubilization suggests that cellulose in the highly lignified residue was inaccessible; indeed, residue from the T→M→T→M treatment was primarily glucan and inert materials (lignin and ash). While C. bescii could significantly solubilize the transgenic switchgrass lines and natural variant tested here, additional or alternative strategies (physical, chemical, enzymatic, and/or genetic) are needed to eliminate recalcitrance.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1394607
Journal Information:
Applied and Environmental Microbiology, Journal Name: Applied and Environmental Microbiology Journal Issue: 17 Vol. 83; ISSN 0099-2240
Publisher:
American Society for MicrobiologyCopyright Statement
Country of Publication:
United States
Language:
English

References (89)

Enzymatic degradation of lignin-carbohydrate complexes (LCCs): Model studies using a fungal glucuronoyl esterase from Cerrena unicolor: Enzymatic Degradation of Lignin-Carbohydrate Complexes journal January 2015
The characterization of pretreated lignocellulosic substrates prior to enzymatic hydrolysis, part 1: A modified Simons' staining technique journal September 2008
Optimization of Hydrothermal Pretreatment of Lignocellulosic Biomass in the Bioethanol Production Process journal November 2012
Genetic Modification of Lignin Biosynthesis for Improved Biofuel Production book October 2010
Dilute Acid and Autohydrolysis Pretreatment book August 2009
Ethanol production by Clostridium thermocellum grown on hydrothermally and organosolv-pretreated lignocellulosic materials journal December 1988
Ethanol production by Clostridium thermocellum grown on hydrothermally and organosolv-pretreated lignocellulosic materials journal December 1988
Morphological changes in the cellulose and lignin components of biomass occur at different stages during steam pretreatment journal January 2014
Genetic modification of lignin biosynthesis for improved biofuel production journal May 2009
Field Evaluation of Transgenic Switchgrass Plants Overexpressing PvMYB4 for Reduced Biomass Recalcitrance journal January 2015
Time Course Field Analysis of COMT-Downregulated Switchgrass: Lignification, Recalcitrance, and Rust Susceptibility journal May 2016
Hydrothermal degradation of polymers derived from plants journal January 1994
A comparison of liquid hot water and steam pretreatments of sugar cane bagasse for bioconversion to ethanol journal January 2002
Fermentation of lignocellulosic hydrolysates. II: inhibitors and mechanisms of inhibition journal August 2000
Biomass yield and quality of 20 switchgrass populations in southern Iowa, USA journal December 2002
Development of switchgrass (Panicum virgatum) as a bioenergy feedstock in the United States journal June 2005
Features of promising technologies for pretreatment of lignocellulosic biomass journal April 2005
Effect of hemicellulose and lignin removal on enzymatic hydrolysis of steam pretreated corn stover journal September 2007
Pretreatments to enhance the digestibility of lignocellulosic biomass journal January 2009
Switchgrass for bioethanol and other value-added applications: A review journal February 2009
Comparison of microwaves to fluidized sand baths for heating tubular reactors for hydrothermal and dilute acid batch pretreatment of corn stover journal May 2011
Simultaneous saccharification and fermentation of Kanlow switchgrass by thermotolerant Kluyveromyces marxianus IMB3: The effect of enzyme loading, temperature and higher solid loadings journal November 2011
Degradation of high loads of crystalline cellulose and of unpretreated plant biomass by the thermophilic bacterium Caldicellulosiruptor bescii journal January 2014
Plant genetic engineering to improve biomass characteristics for biofuels journal June 2006
Lignin plays a negative role in the biochemical process for producing lignocellulosic biofuels journal June 2014
Molecular breeding of switchgrass for use as a biofuel crop journal December 2007
Engineering of plant cell walls for enhanced biofuel production journal June 2015
Plant cell wall reconstruction toward improved lignocellulosic production and processability journal February 2010
Lignocellulosic biomass to bioethanol, a comprehensive review with a focus on pretreatment journal November 2013
MYB transcription factors in Arabidopsis journal October 2010
Lactate formation in Caldicellulosiruptor saccharolyticus is regulated by the energy carriers pyrophosphate and ATP journal May 2010
A comparison of liquid hot water and steam pretreatments of sugar cane bagasse for bioconversion to ethanol journal January 2002
Fermentation of lignocellulosic hydrolysates. II: inhibitors and mechanisms of inhibition journal August 2000
Biomass yield and quality of 20 switchgrass populations in southern Iowa, USA journal December 2002
Hydrothermal Pretreatment and Enzymatic Hydrolysis of Prairie Cord Grass journal January 2010
Hydrothermal Pretreatment of Switchgrass journal April 2011
Significant Differences in the Hydrolysis Behavior of Amorphous and Crystalline Portions within Microcrystalline Cellulose in Hot-Compressed Water journal April 2010
Lignin modification improves fermentable sugar yields for biofuel production journal June 2007
Common processes drive the thermochemical pretreatment of lignocellulosic biomass journal January 2014
Cellulose and lignin colocalization at the plant cell wall surface limits microbial hydrolysis of Populus biomass journal January 2017
Switchgrass as an energy crop for biofuel production: A review of its ligno-cellulosic chemical properties journal January 2010
Carbohydrate and lignin are simultaneously solubilized from unpretreated switchgrass by microbial action at high temperature journal January 2013
Common processes drive the thermochemical pretreatment of lignocellulosic biomass journal January 2014
Cellulose and lignin colocalization at the plant cell wall surface limits microbial hydrolysis of Populus biomass journal January 2017
Net energy of cellulosic ethanol from switchgrass journal January 2008
Genetic manipulation of lignin reduces recalcitrance and improves ethanol production from switchgrass journal February 2011
Direct conversion of plant biomass to ethanol by engineered Caldicellulosiruptor bescii journal June 2014
Multidomain, Surface Layer-associated Glycoside Hydrolases Contribute to Plant Polysaccharide Degradation by Caldicellulosiruptor Species journal January 2016
Multidomain, Surface Layer-associated Glycoside Hydrolases Contribute to Plant Polysaccharide Degradation by Caldicellulosiruptor Species journal January 2016
The Biology and Agronomy of Switchgrass for Biofuels journal September 2005
Transcriptional repression by AtMYB4 controls production of UV-protecting sunscreens in Arabidopsis journal November 2000
Classification of 'Anaerocellum thermophilum' strain DSM 6725 as Caldicellulosiruptor bescii sp. nov. journal October 2009
Lignin Biosynthesis and Structure journal May 2010
Monolignol Pathway 4-Coumaric Acid:Coenzyme A Ligases in Populus. trichocarpa : Novel Specificity, Metabolic Regulation, and Simulation of Coenzyme A Ligation Fluxes journal January 2013
Structure-Function Analyses of a Caffeic Acid O -Methyltransferase from Perennial Ryegrass Reveal the Molecular Basis for Substrate Preference journal December 2010
Thermophilic lignocellulose deconstruction journal May 2014
C aldicellulosiruptor saccharolyticus transcriptomes reveal consequences of chemical pretreatment and genetic modification of lignocellulose journal March 2017
Cell-wall carbohydrates and their modification as a resource for biofuels journal May 2008
Cell-wall carbohydrates and their modification as a resource for biofuels journal May 2008
Functional characterization of the switchgrass (Panicum virgatum) R2R3-MYB transcription factor PvMYB4 for improvement of lignocellulosic feedstocks journal October 2011
Two-year field analysis of reduced recalcitrance transgenic switchgrass journal April 2014
Transgenic switchgrass ( Panicum virgatum L.) targeted for reduced recalcitrance to bioconversion: a 2-year comparative analysis of field-grown lines modified for target gene or genetic element expression journal February 2017
The Path Forward for Biofuels and Biomaterials journal January 2006
Biomass Recalcitrance: Engineering Plants and Enzymes for Biofuels Production journal February 2007
Revealing Nature's Cellulase Diversity The Digestion Mechanism of Caldicellulosiruptor bescii CelA journal December 2013
A Highly Thermostable Kanamycin Resistance Marker Expands the Tool Kit for Genetic Manipulation of Caldicellulosiruptor bescii journal May 2016
Phylogenetic, Microbiological, and Glycoside Hydrolase Diversities within the Extremely Thermophilic, Plant Biomass-Degrading Genus Caldicellulosiruptor journal October 2010
Comparative Analysis of Extremely Thermophilic Caldicellulosiruptor Species Reveals Common and Unique Cellular Strategies for Plant Biomass Utilization journal August 2015
A Highly Thermostable Kanamycin Resistance Marker Expands the Tool Kit for Genetic Manipulation of Caldicellulosiruptor bescii journal May 2016
Phylogenetic, Microbiological, and Glycoside Hydrolase Diversities within the Extremely Thermophilic, Plant Biomass-Degrading Genus Caldicellulosiruptor journal October 2010
Comparative Analysis of Extremely Thermophilic Caldicellulosiruptor Species Reveals Common and Unique Cellular Strategies for Plant Biomass Utilization journal August 2015
Evaluation of ammonia fibre expansion (AFEX) pretreatment for enzymatic hydrolysis of switchgrass harvested in different seasons and locations journal January 2010
Down-regulation of the caffeic acid O-methyltransferase gene in switchgrass reveals a novel monolignol analog journal January 2012
Evaluation of the bioconversion of genetically modified switchgrass using simultaneous saccharification and fermentation and a consolidated bioprocessing approach journal January 2012
Direct glucose production from lignocellulose using Clostridium thermocellum cultures supplemented with a thermostable β-glucosidase journal January 2013
Enhanced characteristics of genetically modified switchgrass (Panicum virgatum L.) for high biofuel production journal January 2013
Consolidated bioprocessing of transgenic switchgrass by an engineered and evolved Clostridium thermocellum strain journal January 2014
Deletion of Caldicellulosiruptor besciiCelA reveals its crucial role in the deconstruction of lignocellulosic biomass journal October 2014
Expression of the Acidothermus cellulolyticus E1 endoglucanase in Caldicellulosiruptor bescii enhances its ability to deconstruct crystalline cellulose journal August 2015
Biological lignocellulose solubilization: comparative evaluation of biocatalysts and enhancement via cotreatment journal January 2016
Consolidated bioprocessing of Populus using Clostridium (Ruminiclostridium) thermocellum: a case study on the impact of lignin composition and structure journal February 2016
Natural genetic variability reduces recalcitrance in poplar journal May 2016
Study of traits and recalcitrance reduction of field-grown COMT down-regulated switchgrass journal January 2017
Effects of Cellulose Crystallinity, Hemicellulose, and Lignin on the Enzymatic Hydrolysis of Miscanthus sinensis to Monosaccharides journal March 2008
Hydrothermal Pretreatment and Enzymatic Hydrolysis of Prairie Cord Grass conference January 2010
The Minor Wall-Networks between Monolignols and Interlinked-Phenolics Predominantly Affect Biomass Enzymatic Digestibility in Miscanthus journal August 2014
Biofuel Component Concentrations and Yields of Switchgrass in South Central U.S. Environments journal March 2005
Designer Plants for Biofuels: A Review journal March 2016
Designer Plants for Biofuels: A Review journal March 2016

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Lignocellulose solubilization and conversion by extremely thermophilic Caldicellulosiruptor bescii improves by maintaining metabolic activity journal May 2019
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Genus-Wide Assessment of Lignocellulose Utilization in the Extremely Thermophilic Genus Caldicellulosiruptor by Genomic, Pangenomic, and Metagenomic Analyses journal February 2018
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