BioEnergy Science Center Research Articles

A new model for the biochemistry of pectin synthesis: GAUTs synthesize diverse HG glycans in structurally and functionally distinct plant cell wall polymers

Each year more than 100 billion tons of carbon dioxide are fixed via photosynthesis into plant biomass, the base of our food chain and a renewable resource for production of chemicals, fuels, materials and bio‐based products. The bulk of plant biomass is plant cell walls, which have evolved during hundreds of millions of years of biotic and abiotic challenge into very complex polymers that support plant longevity up to thousands of years and provide mechanical strength needed for trees to reach heights of 90 meters. Such striking mechanical and physical properties arise from the fine structure of individual wall polymers, the covalent and non‐covalent interactions between them, and the architectural arrangement between the polymers. Among the three major types of cell wall polysaccharides, cellulose, hemicellulose and pectin, pectin is the most complex. Pectin is comprised of the three pectic polysaccharides, homogalacturonan (HG), rhamnogalacturonan I (RG‐I) and rhamnogalacturonan II (RG‐II). Our research focuses on the synthesis of the most abundant pectic polysaccharide, HG, which is a partially methyl‐esterified and acetylated homoglycan of α‐1,4‐linked D‐galacturonic acid. HG is synthesized by the GAUT gene family of 15 proven and putative HG:α‐1,4‐galacturonosyltransferases (HG:GalATs) in Arabidopsis. This family has expanded in grasses and in trees. Our long term goal is to understand which HG glycans are synthesized by the diverse GAUTs, and how the polymers containing these HG glycans contribute to cell wall structure, integrity, plant growth, cell adhesion and plant development. The current biochemical, transgenic and mutant studies showing that at least 6 of the 15 Arabidopsis GAUTs encode HG:GalATs will be summarized and data in support of the hypothesis that different GAUTs synthesize HG glycan regions in unique polymers with different functions in the wall will be presented. Enzymatic properties of a heterologously expressed GAUT1:GAUT7 HG:GalAT complex will be described and a two‐phase model for the non‐processive biosynthesis of homogalacturonan polysaccharides by the GAUT1:GAUT7 complex will be presented. We show that the GAUT1:GAUT7 complex is a distributive glycosyltransferase that catalyzes polymerization of high‐molecular‐weight polysaccharides and has full activity only with acceptors longer than a critical chain length.Support or Funding InformationResearch was supported by USDA AFRI 2010‐65115‐20396 and the BioEnergy Science Center and the Center for Bioenergy Innovation which are US Department of Energy Bioenergy Research Centers supported by the Office of Biological and Environmental Research in the Department of Energy's Office of Science. Also partially funded by Department of Energy Center Grant DESC0015662.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Development and use of a switchgrass (Panicum virgatum L.) transformation pipeline by the BioEnergy Science Center to evaluate plants for reduced cell wall recalcitrance

BackgroundThe mission of the BioEnergy Science Center (BESC) was to enable efficient lignocellulosic-based biofuel production. One BESC goal was to decrease poplar and switchgrass biomass recalcitrance to biofuel conversion while not affecting plant growth. A transformation pipeline (TP), to express transgenes or transgene fragments (constructs) in these feedstocks with the goal of understanding and decreasing recalcitrance, was considered essential for this goal. Centralized data storage for access by BESC members and later the public also was essential.ResultsA BESC committee was established to codify procedures to evaluate and accept genes into the TP. A laboratory information management system (LIMS) was organized to catalog constructs, plant lines and results from their analyses. One hundred twenty-eight constructs were accepted into the TP for expression in switchgrass in the first 5 years of BESC. Here we provide information on 53 of these constructs and the BESC TP process. Eleven of the constructs could not be cloned into an expression vector for transformation. Of the remaining constructs, 22 modified expression of the gene target. Transgenic lines representing some constructs displayed decreased recalcitrance in the field and publications describing these results are tabulated here. Transcript levels of target genes and detailed wall analyses from transgenic lines expressing six additional tabulated constructs aimed toward modifying expression of genes associated with wall structure (xyloglucan and lignin components) are provided. Altered expression of xyloglucan endotransglucosylase/hydrolases did not modify lignin content in transgenic plants. Simultaneous silencing of two hydroxycinnamoyl CoA:shikimate hydroxycinnamoyl transferases was necessary to decrease G and S lignin monomer and total lignin contents, but this reduced plant growth.ConclusionsA TP to produce plants with decreased recalcitrance and a LIMS for data compilation from these plants were created. While many genes accepted into the TP resulted in transgenic switchgrass without modified lignin or biomass content, a group of genes with potential to improve lignocellulosic biofuel yields was identified. Results from transgenic lines targeting xyloglucan and lignin structure provide examples of the types of information available on switchgrass lines produced within BESC. This report supplies useful information when developing coordinated, large-scale, multi-institutional reverse genetic pipelines to improve crop traits.

Global gene expression profiling of two switchgrass cultivars following inoculation with Burkholderia phytofirmans strain PsJN.

Improvement and year-to-year stabilization of biomass yields are primary objectives for the development of a low-input switchgrass feedstock production system using microbial endophytes. An earlier investigation of the effect of Burkholderia phytofirmans strain PsJN on switchgrass germplasm demonstrated differential responses between genotypes. PsJN inoculation of cv. Alamo (lowland ecotype) increased the plant root system, shoot length, and biomass yields, whereas it had no beneficial effect on cv. Cave-in-Rock (upland ecotype). To understand the gene networks governing plant growth promotion responses triggered by PsJN, the gene expression profiles were analysed in these two hosts, following seedling inoculation. The Affymetrix platform switchgrass expressed sequence tag (EST) microarray chip representing 122 972 probe sets, developed by the DOE BioEnergy Science Center, was employed to assess transcript abundance at 0.5, 2, 4, and 8 DAI (days after PsJN inoculation). Approximately 20 000 switchgrass probe sets showed significant responses in either cultivar. Switchgrass identifiers were used to map 19 421 genes in MapMan software. There were apparent differences in gene expression profiling between responsive and non-responsive cultivars after PsJN inoculation. Overall, there were 14 984 and 9691 genes affected by PsJN inoculation in Alamo and Cave-in-Rock, respectively. Of these, 394 are annotated as pathogenesis-related genes. In the responsive cv. Alamo, 68 pathogenesis-related genes were affected, compared with only 10 in the non-responsive cv. Cave-in-Rock. At the very early stage at 0.5 DAI, both cultivars exhibited similar recognition and defence responses, such as genes in signalling and proteolysis, after which the defence reaction in the responsive cv. Alamo became weaker while it was sustained in non-responsive cv. Cave-in-Rock.

Comparison of Different Biomass Pretreatment Techniques and Their Impact on Chemistry and Structure

Pretreatment of lignocellulosic biomass is a prerequisite to overcome recalcitrance and allow enzyme accessibility to cellulose and maximize product recovery for improved economics of second-generation lignocellulosic bio-refineries. Recently, the three US-DOE funded Bioenergy Research Centers (Joint Bioenergy Institute (JBEI), Great Lakes Bioenergy Research Center (GLBRC), and BioEnergy Science Center (BESC)) compared ionic liquid (IL), dilute sulfuric acid (DA), and ammonia fiber expansion (AFEXTM) pretreatments and published comparative data on mass balance, total sugar yields, substrate accessibility, and microbial fermentation (Biotechnology for Biofuels 7: 71; 72 (2014)). In this study, corn stover solids from IL, DA, and AFEX pretreatments were compared to gain comprehensive, in-depth understanding of induced morphological and chemical changes incorporated to corn stover, and how they overcome the biomass recalcitrance. These studies reveal that biomass recalcitrance is overcome by combination of structural and chemical changes to carbohydrates and lignin after pretreatment. Thermal analysis indicates that AFEX and IL pretreated corn stover showed a lower thermal stability while DA pretreated corn stover showed the opposite. The surface roughness variations measured by SANS were correlated to the removal and redistribution of biomass components and was consistent with compositional analysis, AFM and confocal fluorescence imaging results. With AFM and confocal fluorescent microscopy, lignin was found to be re-deposited on cellulose surface with average cellulose fiber width significantly decreased for DA pretreated corn stover (one third of IL and AFEX). HSQC NMR spectra revealed a ~17.9% reduction of β-aryl ether units after AFEX, ~59.8% reduction after DA and >98% reduction after IL. Both NMR and SEC showed similar patterns of lignin depolymerization with highest degree of depolymerization observed for IL followed with DA and AFEX.

A comparative study of ethanol production using dilute acid, ionic liquid and AFEX™ pretreated corn stover.

BackgroundIn a biorefinery producing cellulosic biofuels, biomass pretreatment will significantly influence the efficacy of enzymatic hydrolysis and microbial fermentation. Comparison of different biomass pretreatment techniques by studying the impact of pretreatment on downstream operations at industrially relevant conditions and performing comprehensive mass balances will help focus attention on necessary process improvements, and thereby help reduce the cost of biofuel production.ResultsAn on-going collaboration between the three US Department of Energy (DOE) funded bioenergy research centers (Great Lakes Bioenergy Research Center (GLBRC), Joint BioEnergy Institute (JBEI) and BioEnergy Science Center (BESC)) has given us a unique opportunity to compare the performance of three pretreatment processes, notably dilute acid (DA), ionic liquid (IL) and ammonia fiber expansion (AFEXTM), using the same source of corn stover. Separate hydrolysis and fermentation (SHF) was carried out using various combinations of commercially available enzymes and engineered yeast (Saccharomyces cerevisiae 424A) strain. The optimal commercial enzyme combination (Ctec2: Htec2: Multifect Pectinase, percentage total protein loading basis) was evaluated for each pretreatment with a microplate-based assay using milled pretreated solids at 0.2% glucan loading and 15 mg total protein loading/g of glucan. The best enzyme combinations were 67:33:0 for DA, 39:33:28 for IL and 67:17:17 for AFEX. The amounts of sugar (kg) (glucose: xylose: total gluco- and xylo-oligomers) per 100 kg of untreated corn stover produced after 72 hours of 6% glucan loading enzymatic hydrolysis were: DA (25:2:2), IL (31:15:2) and AFEX (26:13:7). Additionally, the amounts of ethanol (kg) produced per 100 kg of untreated corn stover and the respective ethanol metabolic yield (%) achieved with exogenous nutrient supplemented fermentations were: DA (14.0, 92.0%), IL (21.2, 93.0%) and AFEX (20.5, 95.0%), respectively. The reason for lower ethanol yield for DA is because most of the xylose produced during the pretreatment was removed and not converted to ethanol during fermentation.ConclusionsCompositional analysis of the pretreated biomass solids showed no significant change in composition for AFEX treated corn stover, while about 85% of hemicellulose was solubilized after DA pretreatment, and about 90% of lignin was removed after IL pretreatment. As expected, the optimal commercial enzyme combination was different for the solids prepared by different pretreatment technologies. Due to loss of nutrients during the pretreatment and washing steps, DA and IL pretreated hydrolysates required exogenous nutrient supplementation to ferment glucose and xylose efficiently, while AFEX pretreated hydrolysate did not require nutrient supplementation.

Synthesis of the plant cell wallˈs most complex glycan: pectin ‐ surprises in glycosyltransferase processing and anchoring in the Golgi

Plant cell walls impart structure and identity to plant cells, have roles in growth, development and defense against microbes, and constitute renewal biomass for biofuel and biomaterial production. Plant walls are comprised of cellulose, the matrix polysaccharides pectin and hemicellulose, cell wall proteins and in many secondary walls, lignin. Pectin is the most structurally complex polysaccharide. The Arabidopsis GAUT1‐related gene family encodes 15 GAUT (GAlactUronosylTransferase) and 10 GATL (GAUT‐Like) proteins that are members of CAZy GT8. GAUT1 is a pectin biosynthetic homogalacturonan (HG):galacturononosyltransferase (GalAT) that is part of a Golgilocalized HG:GalAT GAUT1:GAUT7 core complex. GAUT1 is proteolytically processed and its transmembrane domain removed, leaving the question of how GAUT1 is retained in the Golgi lumen. Biochemical and fluorescent fusion‐protein studies show that GAUT1 is anchored in the Golgi lumen by a reducing agent‐sensitive association with GAUT7. Immunoadsorption of the GAUT1:GAUT7 complex and mass spectrometry identified 12 additional putative GAUT protein complex members whose identities suggest that pectin synthesis may occur as domains. The recent identification of a novel wall glycoconjugate structure is consistent with this view. The data support a role for GAUTs in synthesizing diverse pectic cell wall domains in primary and secondary walls. Funding from USDA AFRI 2010‐65115‐20396; NSF‐MCB 0646109, DOE DE‐FG02‐09ER20097 and BioEnergy Science Center grant DE‐PS02‐06ER64304. BioEnergy Science Center is a U.S. Department of Energy Bioenergy Research Center supported by Office of Biological and Environmental Research in DOE Office of Science.

BESC knowledgebase public portal

The BioEnergy Science Center (BESC) is undertaking large experimental campaigns to understand the biosynthesis and biodegradation of biomass and to develop biofuel solutions. BESC is generating large volumes of diverse data, including genome sequences, omics data and assay results. The purpose of the BESC Knowledgebase is to serve as a centralized repository for experimentally generated data and to provide an integrated, interactive and user-friendly analysis framework. The Portal makes available tools for visualization, integration and analysis of data either produced by BESC or obtained from external resources.Availability: http://besckb.ornl.govContact: syedmh@ornl.gov

Co-hydrolysis of hydrothermal and dilute acid pretreated populus slurries to support development of a high-throughput pretreatment system

BackgroundThe BioEnergy Science Center (BESC) developed a high-throughput screening method to rapidly identify low-recalcitrance biomass variants. Because the customary separation and analysis of liquid and solids between pretreatment and enzymatic hydrolysis used in conventional analyses is slow, labor-intensive and very difficult to automate, a streamlined approach we term 'co-hydrolysis' was developed. In this method, the solids and liquid in the pretreated biomass slurry are not separated, but instead hydrolysis is performed by adding enzymes to the whole pretreated slurry. The effects of pretreatment method, severity and solids loading on co-hydrolysis performance were investigated.ResultsFor hydrothermal pretreatment at solids concentrations of 0.5 to 2%, high enzyme protein loadings of about 100 mg/g of substrate (glucan plus xylan) in the original poplar wood achieved glucose and xylose yields for co-hydrolysis that were comparable with those for washed solids. In addition, although poplar wood sugar yields from co-hydrolysis at 2% solids concentrations fell short of those from hydrolysis of washed solids after dilute sulfuric acid pretreatment even at high enzyme loadings, pretreatment at 0.5% solids concentrations resulted in similar yields for all but the lowest enzyme loading.ConclusionsOverall, the influence of severity on susceptibility of pretreated substrates to enzymatic hydrolysis was clearly discernable, showing co-hydrolysis to be a viable approach for identifying plant-pretreatment-enzyme combinations with substantial advantages for sugar production.

Bioenergy research: a new paradigm in multidisciplinary research.

The field of biology is becoming increasingly interdisciplinary and cross-cutting. This changing research atmosphere is creating the way for a new kind of enquiry that while building upon the traditional research establishment is providing a new multidisciplinary framework to more effectively address scientific grand challenges. Using the US Department of Energy sponsored BioEnergy Science Center as an example, we highlight how impactful breakthroughs in biofuel science can be achieved within a large cross-disciplinary team environment. Such transformational insights are key to furthering our understanding and in generating models, theories and processes that can be used to overcome recalcitrance of biomass for sustainable biofuel production. Multidisciplinary approaches have an increasingly greater role to play in meeting rising demands for food, fibre, energy, clean environment and good health. Discoveries achieved by diverse minds and cross-applications of tools and analytical approaches have tremendous potential to fill existing knowledge gaps, clear roadblocks and facilitate translation of basic sciences discoveries as solutions towards addressing some of the most pressing global issues.

ORIGINAL RESEARCH: Lignocellulose recalcitrance screening by integrated high-throughput hydrothermal pretreatment and enzymatic saccharification

We report a novel 96-well multiplate reactor system for comparative analysis of lignocellulose recalcitrance via integrated hydrothermal pretreatment and enzymatic saccharification. The system utilizes stackable nickel/gold-plated 96-well aluminum reactor plates, a clamping device fit to a standard Parr reactor, and robotics for efficient liquids and solids handling. A capacity of 20 plates allows up to 1,920 separate hydrothermal reactions per run. Direct and rapid analysis of key end-products, glucose and xylose, is facilitated by the use of glucose oxidase/peroxidase and xylose dehydrogenase-linked assays. To demonstrate efficacy, a set of 755 poplar core samples from the US Department of Energy’s BioEnergy Science Center was tested. Total sugar release ranged from 0.17 to 0.64 g/g of biomass and correlated strongly with the ratio of syringyl to guaiacyl lignins in the samples. Variance among sample replicates was sufficiently minimal to permit clear assignment of differences in recalcitrance throughout this large sample set.

Developmental Control of Lignification in Stems of Lowland Switchgrass Variety Alamo and the Effects on Saccharification Efficiency

The switchgrass variety Alamo has been chosen for genome sequencing, genetic breeding, and genetic engineering by the US Department of Energy Joint Genome Institute (JGI) and the US Department of Energy BioEnergy Science Center. Lignin has been considered as a major obstacle for cellulosic biofuel production from switchgrass biomass. The purpose of this study was to provide baseline information on cell wall development in different parts of developing internodes of tillers of switchgrass cultivar Alamo and evaluate the effect of cell wall properties on biomass saccharification. Cell wall structure, soluble and wall-bound phenolics, and lignin content were analyzed from the top, middle, and bottom parts of internodes at different developmental stages using ultraviolet autofluorescence microscopy, histological staining methods, and high-performance liquid chromatography (HPLC). The examination of different parts of the developing internodes revealed differences in the stem structure during development, in the levels of free and well-bound phenolic compounds and lignin content, and in lignin pathway-related gene expression, indicating that the monolignol biosynthetic pathway in switchgrass is under complex spatial and temporal control. Our data clearly show that there was a strong negative correlation between overall lignin content and biomass saccharification efficiency. The ester-linked p-CA/FA ratio showed a positive correlation with lignin content and a negative correlation with sugar release. Our data provide baseline information to facilitate genetic modification of switchgrass recalcitrance traits for biofuel production.

Bioenergy

The biofuels database provides information on fuel compounds, metabolic pathways, enzymes and microorganisms. It also contains comparative information on similar molecules made by chemical processes. This website allows users to search for protein structures for enzymes important in the process of making biofuels. Users can search on an enzyme name or the name of a bacterium. The alternative fuels data resource was developed by the Department of Energy. It provides information on biofuels and efficient uses of energy. This page provides a library of bioenergy documents and links to related resources. Oilgae is devoted to the use of algae to make fuels. It contains information and also serves as a networking forum. The biofuels gallery contains a listing of names and chemical structures for compounds known to be important fuels. Links can be followed for further information on the compounds. This site by the U.S. Department of Agriculture discusses bioenergy and the general issue of fuel versus food. This wiki page provides a nice general overview on bioenergy. This is one person's list of the ‘top’ companies in the bioenergy field. This page is a gateway to information on biomass feedstocks: forestry residue, herbaceous crops, agricultural residue, municipal residue, oil crops, and woody crops. The Great Lakes Bienergy Center is one of three bioenergy centers supported by the U.S. Department of Energy. The webpage provides links to its programs and resources. The BioEnergy Science Center is one of three bioenergy centers supported by the U.S. Department of Energy. The webpage provides links to its programs and resources. The Joint BioEnergy Institute is one of three bioenergy centers supported by the U.S. Department of Energy. The webpage provides links to its programs and resources. This web brochure provides educational material for laboratory exercises connected to deriving fuels from forest resources. This site focuses on the plant side of biofuel production. It contains some useful links to further information. This national center focuses on all areas of renewable energy including biofuels. Amyris is a company that has transferred technology for producing sesquiterpene compounds into a venture for making next-generation hydrocarbon biofuels. Gevo is a biofuels company. Their major technology is based on engineered bacteria that produce long chain alcohols. The Mascoma Company focuses on converting cellulosic biomass to ethanol. Solazyme is a company that develops technology based on photosynthetic microbes for generating renewable energy. This site focuses on biodiesel. Links to additional information from other sites is also provided.

Biofuels, Bioenergy, and Bioproducts from Sustainable Agricultural and Forest Crops

This issue of BioEnergy Research highlights the Short Rotation Crops International Conference held in Bloomington, Minnesota in August 2008. This is the first special issue of BioEnergy Research, with several additional special issues planned in the next year, focused on the three U.S. Department of Energy Bioenergy Research Centers (Great Lakes Bioenergy Research Center, BioEnergy Science Center, and Joint BioEnergy Institute), and emerging technologies for biodiesel production. The purpose of these special issues is to highlight emerging research efforts in the areas of biomass, biofuels, and bioenergy. The Short Rotation Crops International Conference represented a unique opportunity for communication and interaction between researchers working on herbaceous and woody bioenergy feedstocks, one that we hope will continue to stimulate new interactions and creative solutions for bioenergy and bioproducts. We invite other groups to submit ideas for future special issues to one of the three co-Editors-inChief of BioEnergy Research. For quite some time, there has been a substantial need for an international conference integrating biological and social aspects of producing both herbaceous and woody crops for biofuels, bioenergy, and bioproducts. Increasing energy prices worldwide have made alternative sources economically feasible in recent times. Therefore, given substantial support from 26 sponsors representing both agricultural and forestry sectors, the Short Rotation Crops International Conference: Biofuels, Bioenergy, and Bioproducts from Sustainable Agricultural and Forest Crops was held in Bloomington, Minnesota during August 2008. This meeting combined world-leaders in herbaceous and woody biomass energy crops to present more than 90 papers on the state-of-the-art in sustainable energy production and policy. The conference goal was to create an international forum to strengthen old collaborations and create new partnerships to attack some of the pressing issues facing the world’s demand for energy. This special issue represents many of the extensive efforts underway to help understand these issues. We hope this collection will help to spark further conversations among scientists, academicians, regulators, and the general public. We encourage you to contact the authors to cultivate such discussions. M. D. Casler U.S. Department of Agriculture, Agricultural Research Service, U.S. Dairy Forage Research Center, 1925 Linden Drive, Madison, WI 53706, USA

Driving Biofuels from Field to Fuel Tank

Rising oil prices, fears of global warming, and instability in oil-producing countries have ignited the rush to produce biofuels from plants. The science is progressing rapidly, driven by favorable policies and generous financing, but many hurdles remain before cars and trucks run on "gasohol" or "grassoline."

The DOE BioEnergy Science Center—a U.S. Department of Energy Bioenergy Research Center

The BioEnergy Science Center, a nationally and internationally peer-reviewed center of leading scientific institutions and scientists, is organized and in operation as a U.S. Department of Energy Bioenergy Research Center. This Oak Ridge National Laboratory-led Center has members from top-tier universities, leading national labs, and private companies organized as a single project team, with each member chosen for its significant contributions in the Center’s research focus areas. The recalcitrance of cellulosic biomass is viewed as (1) the most significant obstacle to the establishment of a cellulosic biofuels industry, (2) essential to producing cost-competitive fuels, and (3) widely applicable, since nearly all biofuels and biofeedstocks would benefit from such advances. The mission of the BioEnergy Science Center is to make revolutionary advances in understanding and overcoming the recalcitrance of biomass to conversion into sugars, making it feasible to displace petroleum with ethanol and other fuels.

Renewable fuels

This site promotes knowledge for the development of fuels from renewable resources with a focus on microbially based metabolic transformations. Chemical processes for generating fuel molecules are also included so users can compare and contrast different processes. The AOC is broadly concerned with oils, fats and surfactants. With the emerging interest in biofuels, the AOC website has increasingly put up content on biodiesel and other biofuel issues. This site focuses on biodiesel. It is an excellent resource on the use and handling of biodiesel. Links to additional information from other sites is also provided. The alternative fuels data centre is designed to help society reduce dependence on petroleum. This includes the use of alternative fuels, many of which are microbially based biofuels. This website provides extensive information on biofuels, biomass resources and biofuels economics. It contains summaries of biofuels research projects in Europe. This web article put up by the American Society for Microbiology provides a good overview of biofuels with a particular emphasis on microbiological aspects. This site provides a tutorial on biofuels and links to biofuels research ongoing at the National Renewable Energy Laboratory. This page provides an excellent overview of the biofuels area. It contains references with linkages to additional information. This web article focuses on national biofuels science and policy. It was recently published in Chemical and Engineering News. The Bioenergy Wiki is an interactive site where people can post and trade information. It is less of a scientific resource and more of a business and networking resource. This web tutorial is put out by the United States Department of Energy. It caters to students who are developing an interest in biofuels and seeking general information. This web page serves as a clearinghouse for government reports pertaining to biofuels. These can be read as html files or downloaded by users. This site contains much information on the use of algae to produce fuel compounds. Its greatest value is the large number of links provided to numerous other sites that deal with issues related to growing or processing algae for oil. Materials such as coal can be converted chemically to carbon monoxide, hydrogen and carbon dioxide. Some anaerobic bacteria can be interfaced with such chemical processes to produce ethanol or other fuel molecules. This web page provides a large number of links to biofuels resources. The Bioenergy Science Center website highlights activities at one of the three new Department of Energy biofuels centres. The Great Lakes Bioenergy Research Center website highlights activities at one of the three new Department of Energy biofuels centres. The Joint BioEnergy Institute website highlights activities at one of the three new Department of Energy biofuels centres.

Research and Findings

New Method Developed to Identify Genetic Determinants of Alzheimer's Disease. India Launches First Biofuels and Bioenergy Science Center.