Biomass Formation and Modification
Biomass Deconstruction and Conversion
Natural Biocatalysts Outperform Industry Standard
Comparative study finds heat-loving microbes could reduce the need for thermochemical pretreatment
In the most comprehensive controlled comparison to date of lignocellulosic solubilization by various biocatalysts, BESC researchers found that naturally cellulolytic microbes such as Clostridium thermocellum (stained green and growing on poplar tissue in image) achieved significantly higher solubilization yields over commercial pretreatment systems. [Image courtesy ORNL]Read More
Promise of Unusual Lignin Polymer as Feedstock for Carbon Fiber
Stronger, Lighter Carbon Fiber Could Be Used in Parts for Cars, Aircraft, Electronics, and Sports Equipment
BESC researchers discovered an unusual lignin polymer in the seed coats of vanilla beans (pictured) that is naturally biosynthesized from caffeyl (C) alcohol. In contrast to lignin polymers that are highly cross-linked, C-lignin is a linear polymer, which makes it easier to process into high-quality carbon fibers. [Image courtesy iStock]Read More
Identification of Poplar Adaptation Mechanisms
Findings Could Lead to More Efficient Ways of Breeding High-Ethanol-Yielding Poplar and Other Tree Species
Using whole-genome sequencing and high-throughput phenotyping, BESC researchers were able to rapidly pinpoint gene mutations responsible for causing low lignin levels in poplar trees planted in a variety of environmental conditions. This proof-of-concept will allow researchers to tag genes associated with other economically important but complex plant traits. [Image courtesy BESC]Read More
Beneficial Plant Gene Discovery
Research Lays Groundwork for New Ways of Manipulating Plants
BESC researchers discovered a previously uncharacterized gene (GXMT1), which directs a key step in the development of xylan, a principal component of cell walls in plants such as Arabidopsis (pictured). Characterizing this gene, which makes the plant resistant to biofuel conversion, will lead to improved strategies for modifying such cell wall structures to help turn plants into biofuel more efficiently. [Image courtesy iStock]Read More
Molecular Structure of Plant Biomass
Imaging Reveals Enzymes in Action and Significance of Plants' Nanoscale Architecture
Plant cell walls contain networks of cellulose microfibrils that can be broken down into sugars for fuel and complex polymers that shield the cellulose from enzymatic attack. To characterize cell wall structure at the subnanometer scale and assess its response to chemical pretreatment, BESC developed techniques to image enzyme digestion in real time, revealing that biomass reactivity is determined by the nanoscale architecture of plant cell walls.Read More
A Leap Forward in Microbial Ethanol Yields
Engineered yeast converts up to 97% of plant sugars into fuel
Scientists at BESC and research partner Mascoma LLC have developed an advanced strain of Saccharomyces cerevisiae that sets a new standard for conversion of biomass sugars from pretreated corn stover. While conventional yeast (pictured) leaves more than one-third of plant sugars unused in the form of xylose, the C5 FUEL™ microbe efficiently converts this xylose into ethanol in less than 48 hours.Read More
Real-World Performance of Low-Lignin Switchgrass
Field study assesses sugar release and ethanol yield in transgenic feedstock
Lignin in the cell walls of switchgrass and other bioenergy feedstocks severely limits the accessibility of cell wall carbohydrates to enzymatic breakdown into fermentable sugars and subsequently biofuels. In the first reported study of its kind, the biofuel potential of transgenic switchgrass with reduced lignin content was evaluated over two growing seasons.Read More
Using a "commercialization council" of technology transfer and intellectual property (IP) management professionals from partner institutions, BESC evaluates the commercial potential of new inventions arising from BESC research and promotes and facilitates the licensing of BESC IP.
BESC's education program, which is 75% self-sustaining, takes a novel approach. BESC has developed lesson plans to educate students about energy production and utilization. BESC uses a hub-and-spoke approach of working through regional science centers to maximize hands-on access and adaptation to local conditions.
Progress to Date
Brian Davison elected Fellow of the AIChE
Dramatic performance of Clostridium thermocellum explained by its wide range of cellulase modalities
January 12, 2016
Optimizing Biocatalyst-Feedstock Combinations to Achieve High Solubilization with Minimal Pretreatment
This study carried out the most comprehensive controlled comparison to date of lignocellulosic solubilization by various biocatalysts, and report initial exploration of enhancing microbial solubilization of cellulosic biomass via mechanical disruption (cotreatment). Trends drawn from time-course and end-point data for six conversion systems and three substrates were: greater-than-expected differences in the effectiveness of various biocatalysts; lower yields and greater dependence on particle size for Populus as compared to green or senescent switchgrass; equal fractional solubilization of glucan and xylan with no biological solubilization of the non-carbohydrate fraction of biomass; and two-fold increase in solubilization via mechanical disruption with greater benefits on partially-fermented feedstock.
January 06, 2016
Review: How Plant Cell Wall NMR Provides Insights Into Biomass Chemistry and Structures
The structure of the plant cell wall and recalcitrance are intimately tied together such that fundamental breakthroughs in recalcitrance have driven the science of biomass characterization. Work from BESC and other energy centers has dramatically enhanced the resolution and productivity of Nuclear Magnetic Resonance (NMR) analysis of biomass polymers including lignin, cellulose and hemicellulose. Whole cell NMR analysis, as reviewed in this article, provides a relatively facile means of characterizing changes in lignin and hemicellulose that contribute to reduced recalcitrance in pretreated biomass and/or transgenic or natural variant plant species.
December 31, 2015
Successful Transfer of Transgenic Switchgrass Low-Recalcitrance Traits into High-Yielding Field Variety
This study evaluated the feasibility of transferring the low-recalcitrance traits associated with a transgenic switchgrass line into high-yielding field varieties in an attempt to improve growth-related traits and to preserve the transgenic benefit. Our results provide insights into the possible improvement of switchgrass productivity via biotechnology paired with plant breeding.
December 26, 2015
Review: Potential Impact of S. vermifera, A Unique Root Symbiont, On Agronomics of Biofeedstocks
Research performed with orchid mycorrhizal fungus Sebacina vermifera clearly indicates significant growth-promoting abilities in a remarkably broad spectrum of plants, including switchgrass, that rivals or even surpasses that of arbuscular mycorrhizae. Sebacinoid fungi should be considered as a previously hidden, but amenable and effective microbial tool for enhancing plant productivity and stress tolerance which has been validated in switchgrass, an important biofeedstock for biofuels.
December 14, 2015
Towards Understanding Gene Systems Mediating Redox Homeostasis and Energy Metabolism in C. thermocellum
Current moderate ethanol yields and productivities as well as growth inhibition impede industrial deployment of this bacterium for commodity fuel production. Redox imbalances may contribute to incomplete substrate utilization, limit bioproductivity, and direct fermentation products to undesirable overflow metabolites. The redox systems identified are active and fungible in C. thermocellum upon introduction of a redox stress, and considered a link between redox stress and the occurrence of ethanol yield-limiting, unwanted metabolic processes. This expression study informs ongoing metabolic engineering efforts to increase bioproductivity in C. thermocellum.
December 10, 2015
Commercial Licensing of a BESC Global Genetic Regulator of Aromatic Biosynthesis
BESC has been studying SNPs and key compositional and conversion phenotypes in the natural variation population in Populus using GWAS (genome-wide association studies). A study of rare SNPs identified an unusual paralog in Populus which had taken on new regulator functions. Patent applications have been filed. Follow-on work is testing the utility in other plant species. The technology is being licensed to two companies who plan to commercialize the technology: GreenWood Resources and Forest Genetics International. Increasing biofuel yield or forage digestibility can lead to reductions in land use for these crops and thus contributing to long term sustainability.