Highlights Archive

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December 30, 2014

Data from M. Nar and N. D’Souza, University of North Texas

Discovery of C-lignin shows promise as feedstock for carbon fiber
The higher purity of C-lignin over Kraft fibers and PAN-based fibers is expected to translate into higher mechanical stiffness, thermal and electrical conductivity.

December 30, 2014


BIOFUELS lessons on Outreach site
BESC has an ongoing outreach effort with the Creative Discovery Museum (CDM) of Chattanooga, Tennessee. targeting 4th through 8th grades and their families. This successful program has reached over 115,000 students and parents to date through the Farming For Fuels curriculum and activities.

December 16, 2014

Identification of key transcription factor that controls chlorophyll degradation and leaf senescence
This represents the first confirmation of NAP in positive regulation of ABA biosynthesis in Arabidopsis, and thus a key factor in induction of chlorophyll degradation genes and plant senescence.

December 16, 2014

Young, middle-aged, and senescent tillers

Switchgrass transcription factors linked to nutrient efficiency in senescence
This study confirms that PvNAC1 and PvNAC2 play conserved roles in leaf senescence in switchgrass and hold promise for improving nutrient use efficiency in switchgrass through genetic manipulation or breeding.

December 03, 2014

Toward improving tolerance of thermophilic microorganisms to pretreatment inhibitors
A heat-stable furfural reductase has been identified in T. pseudethanolicus 39E for inhibitor detoxification. It promises rational improvement in tolerance and has already shown promising results when expressed in the cellulolytic thermophile, C. bescii (in preparation).

December 01, 2014

The thermodynamic origin of the reduced lignin-hemicellulose association is found to be a more favor (...more)

ORNL TITAN supercomputer used to determine molecular basis of reduced recalcitrance
Reduced lignin-hemicellulose association increases the cell wall porosity in the mutant plants, thus explaining their easier deconstruction to biofuels. This work illustrates how MD simulations can be a useful tool for predicting and explaining the effects of changes in plant genotypes on cell wall phenotypes.

November 25, 2014

Simons' stain dye adsorption diagram for NaOH-, Ca(OH)2-, and ammonia-pretreated Populus.

Characterization of various alkaline pretreatment methods on cellulose structure and accessibility (A joint BESC/ORNL Biofuels SFA effort)
The study identifies important cellulose structural features and relevant parameters related to biomass recalcitrance and the changes that occur in cellulose structure and accessibility upon a variety of low-cost and mild alkaline treatments and determines some of the key factors responsible for biomass recalcitrance.

November 11, 2014

Synthetic AOR/AdhA Pathway for Bioalcohol Production from Sugar (top) or from Organic Acids with H2 or CO2

Development of a synthetic metabolic pathway for sugar to bioalcohol production in thermophilic microorganisms
The AOR/AdhA pathway is a new energy-conserving, redox-balanced route for sugar to ethanol conversion that could potentially be used in any CBP microorganism. Carbon monoxide and hydrogen gas (syngas) can be used as the driving force for bioalcohol production from a range of aliphatic and aromatic aldehydes, and is a potentially game-changing strategy for syngas fermentation.

November 02, 2014

Expression patterns of the three putative C20 GA2ox genes among tissues and developmental stages in switchgrass as determined by zRT-PCR.

Overexpression of gibberellin 2-oxidases leads to reduced recalcitrance in switchgrass
Results suggest that overexpression of GA2ox genes in switchgrass is a feasible strategy to improve plant architecture and reduce biomass recalcitrance for biofuel.

October 10, 2014

Symposium on Biotechnology for Fuels and Chemicals and Annual World Congress on Industrial Biotechnology
Bioenergy Research Centers Update and DOE Bioenergy Research Centers Achievements

October 10, 2014

BioEnergy Science Center 2014 Science Retreat Chattanooga, Tennessee

BioEnergy Science Center 2014 Science Retreat Chattanooga, Tennessee
BioEnergy Science Center 2014 Science Retreat Chattanooga, Tennessee

October 07, 2014

Morphology and cell wall composition of Populus deltoides plants overexpressing UGPase relative to (...more)

Overexpression of key cellulose biosynthesis precursor enzyme, UGPase, reveals altered sugar and secondary metabolism in Populus
This study provides evidence that manipulation of sugar metabolizing enzymes, such as UGPase, can have qualitative and quantitative effects on secondary metabolic pathways of shikimate, phenylpropanoid, and lignin biosynthesis. A cross-collaborative BESC effort is investigating the substrate preferences and reaction kinetics of UGPase to understand the observed pleiotropic phenotype. In integration with assessments of effects of other gene sequence and expression variations, our studies are yielding critical insights into biomass formation in Populus.

October 01, 2014

New Insights into Biomass Deconstruction from Deletion of Genes in Caldicellulosiruptor
Three papers report the first in vivo analyses of genes predicted to be important for plant biomass deconstruction in the context of the entire suite of enzymes in Caldi. This demonstrates the potential of identifying and engineering enzymes to improve both substrate utilization and the range of substrates utilized. This is an example of using microbial deconstruction capabilities to probe important plant cell wall structures such as pectin.

September 14, 2014

MALDI-TOF MS of the products in the absence and presence of IRX10-L, consistent with the sequential (...more)

Discovery of two key enzymes in xylan synthesis and acetylation in plant cell walls
Two key enzymes for two critical process in xylan (and secondary plant cell wall) synthesis have now been identified, purified and confirmed. These finding will accelerate our understanding and ability to manipulate plant cell wall structures for advanced renewable feedstocks for conversion into sugars and fuels or into valuable products such as biomaterials.

September 02, 2014

Process scheme for a closed-loop biorefinery using ILs derived from lignocellulosic biomass

Ionic Liquids (ILs) derived from biomass – provide an effective biomass pretreatment
Deriving ILs from lignocellulosic biomass shows significant potential for the realization of a “closed-loop” process for future lignocellulosic biorefineries and has far-reaching economic impacts for other IL-based conversion technology currently using ILs synthesized from petroleum sources.

August 24, 2014

Locations of plantations (yellow diamonds) and tree collections. Colors indicate genetically differentiated groups.

Genome-wide adaptive variation in Populus trees revealed by massive population genomic analysis
This study is the first to explore the genomic legacy of selection across an entire tree genome and highlight both the wide range of selection pressures as well as the climatic influence on phenological systems and growth. This study provides new insights into mechanisms of adaptive evolution, and provides potential targets for genetic improvement for biofuels production as well as the management of natural populations in the face of environmental change.

August 16, 2014

Linville, et al., “Transcriptomic analysis of Clostridium thermocellum Populus hydrolysate-tolerant (...more)

Clostridium thermocellum develops increased cellular efficiency to tolerate Populus hydrolysate
A conceptual model of the improved mutant strain was developed, which provides a summary of the major mutations and related changes in gene expression or pathway activities. These changes resulted in an overall increase in cellular efficiency of the hydrolysate-tolerant organism by increased overall energy production and conversion rather than specific tolerance genes. In contrast, the wild type response to inhibition appears as decreased growth and increased expression of stress response genes. These results suggest new global strategies for engineering the development of increased tolerance to biomass hydrolysates in microbial processes used for biofuel production.

August 05, 2014

Gene co-expression networks for Arabidopsis PrR1 and PrR2. (A) PrR1 is co-expressed with many known (...more)

New relationship between lignan biosynthesis and lignin distribution in secondary cell wall structure in Arabidopsis
Provides new evidence for a relationship between lignan synthesis and the role of lignin in secondary plant cell wall structure, which may shed light on evolution of plant secondary wall structure. Further analysis of this relationship may provide strategies for reducing recalcitrance of lignocellulosic biomass while enhancing plant defense.

June 03, 2014

16S rRNA tree of the 40 Clostridium genomes: biomass degraders (red),animal pathogens (blue), other (black)

Comparative Analysis of 40 Genomes provides new insights into biomass degradation by Clostridia
New insights provided by this analysis could provide useful information to mechanistic studies of biomass degradation and the range of metabolic pathways in Clostridia. This range of pathways may aid to designing or improving more efficient biomass degraders. Note: Over 100 clostridial genomes have now been sequenced (2014); therefore these types of analyses will need to be repeated on a regular basis as more genomes become available.

June 02, 2014

Lactate, acetate and ethanol production by wild-type (I), ldh- (J), and ldh-AdhE+ (K) strains of C bescii grown on non-pretreated switchgrass

Direct conversion of biomass to biofuel without pretreatment using engineered Caldicellulosiruptor bescii
This work reports the direct conversion of plant biomass to a fuel without pre-treatment which is the major economic barrier to commercialization It is also the first demonstration of metabolic engineering of an extreme thermophilic organism for conversion of lignocellulosic biomass to a liquid fuel

May 22, 2014

Conversion (mg/g glucan loaded) for C. thermocellum mutant M1570 and wild-type DSM 1313 strains on b (...more)

Improved production from modified switchgrass when combined with an engineered C. thermocellum strain
This is the first report of the use of a microbe engineered to produce increased amounts of a biofuel on a bioenergy feedstock that has been modified for the same purpose. The results demonstrate the potential additive advantages from combining a modified feedstock with an engineered consolidated bioprocessing microorganism.

May 15, 2014

Ragauskas, et al., “Lignin valorization: improving lignin processing in the biorefinergy,” Science, 2014

Lignin Valorization: Improving Lignin Processing in the Biorefinery is outlined in Science
This perspective review offers a rationale for optimism that more value can be derived from lignin within a biorefinery due to current and project research

May 13, 2014

Glucose yields in solution following enzymatic hydrolysis of dilute acid (DA), ammonia fiber expansi (...more)

Comparison of Enzymatic Reactivity of Corn Stover Solids
Initial hydrolysis yields were highest for substrates with greater lignin removal, a greater degree of change in cellulose crystallinity, and high enzyme accessibility. Final glucose yields could not be clearly related to concentrations of xylooligomers released from xylan during hydrolysis. Overall, none of these factors could completely account for differences in enzymatic digestion performance of solids produced by AFEX, DA, and IL pretreatments.

April 30, 2014

Lin, et al., “Isobutanol production at elevated temperatures in thermophilic Geobacillus thermoglucosidasius,” Metabolic Engineering 24, 1-8, 2014

Microbial production of isobutanol at elevated temperatures
First demonstration of isobutanol production on a recombinant bacterium at elevated temperature

April 21, 2014

University of Tennessee switchgrass

Field study of COMT transgenic switchgrass
The lignin-modified transgenic switchgrass had similar gains in sugar release (up to 34% higher) and biofuel production (up to 28% higher) as observed when comparing transgenic and control plants grown in the greenhouse. The greenhouse-grown experimental plant tissue was live and green, compared with the senesced, brown tissue harvested at the end of the growing season from the field experiments. The COMT2 transgenic event yielded over 50% more liters of ethanol per hectare compared with the control, which demonstrates that transgenic feedstocks could make important improvements in lignocellulosic biofuels.

March 21, 2014

Brown, S. D. et al., “Comparison of single-molecule sequencing and hybrid approaches for finishing t (...more)

Genomic analysis of the industrially relevant Clostridium autoethanogenum genome reveals potential role for CRISPR systems
This study demonstrates value of PacBio single molecule sequencing in producing single contig finished genomes. Potential associations between plasmid content and CRISPR systems may have implications for historical industrial scale Acetone-Butanol-Ethanol (ABE) fermentation failures and future large scale bacterial fermentations.

March 03, 2014

Dr. Arthur J. Ragauskas

Art Ragauskas Named Fourteenth University of Tennessee Oak Ridge National Laboratory Governor’s Chair
Dr. Arthur J. Ragauskas will serve as Governor’s Chair for Biorefining, based in the University of Tennessee’s (UT) Department of Chemical and Biomolecular Engineering with a complementary appointment in the UT Institute of Agriculture’s Department of Forestry, Wildlife, and Fisheries. He will serve in the Oak Ridge National Laboratory (ORNL) Energy and Environmental Sciences Directorate, Biosciences Division, and as a member of the Department of Energy’s (DOE) BioEnergy Science Center (BESC).

March 01, 2014

Creative Discovery Museum

BESC Communicates to Science Museum Community on Farming for Fuels Outreach Program
Farming for Fuels has grown into a program with a national presence and is currently being used in 20 science centers and museums in 12 states; over 80,000 people across the United States have now participated in the program. The journal in which this article appears was circulated to nearly 600 science-technology museums in over 40 countries, greatly increasing the awareness of this program across the museum educational community.

January 31, 2014

BESC Inventions, Licenses and Patents Awarded

BESC – Awarded Patents – FY2014
BESC – Awarded Patents – FY2014

BioEnergy Science Center one of three DOE Bioenergy Research Centers established by the U.S. Department of Energy.