[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
Researchers engineer new pathway in E. coli to produce renewable propane
April 15, 2015
Researchers at The University of Manchester, Imperial College London and University of Turku have made an advance toward the renewable biosynthesis of propane with the creation of a new synthetic pathway in E. coli, based on a fermentative butanol pathway. An open access paper on the work is published in the journal Biotechnology for Biofuels.
In 2014, members of the team from Imperial College and the University of Turku had devised a synthetic metabolic pathway for producing renewable propane from engineered E. coli bacteria, using pathways based on fatty acid synthesis. (Earlier post.) Although the initial yields were far too low for commercialization, the team was able to identify and to add essential biochemical components in order to boost the biosynthesis reaction, enabling the E. coli strain to increase propane yield. Yields, however, were still too low.
UC Berkeley hybrid semiconductor nanowire-bacteria system for direct solar-powered production of chemicals from CO2 and water
April 10, 2015
Researchers at UC Berkeley have developed an artificial photosynthetic scheme for the direct solar-powered production of value-added chemicals from CO2 and water using a two-step process involving a biocompatible light-capturing nanowire array with a direct interface with microbial systems.
As a proof of principle, they demonstrated that, using only solar energy input, such a hybrid semiconductor nanowire–bacteria system can reduce CO2 at neutral pH to a wide array of chemical targets, such as fuels, polymers, and complex pharmaceutical precursors A paper on their work is published in the ACS journal Nano Letters.
Virginia Tech team engineers optimized synthetic enzymatic pathway for high-yield production of H2 directly from biomass
April 07, 2015
A team of Virginia Tech researchers and colleagues has demonstrated the complete conversion of glucose and xylose from pretreated plant biomass to H2 and CO2 based on an in vitro synthetic enzymatic pathway crafted from more than 10 purified enzymes. Glucose and xylose were simultaneously converted to H2 with a yield of two H2 per carbon, the maximum possible yield.
The researchers used a nonlinear kinetic model fitted with experimental data to identify the enzymes that had the greatest impact on reaction rate and yield. After optimizing enzyme loadings using this model, volumetric H2 productivity was increased 3-fold to 32 mmol H2⋅L−1⋅h−1. The productivity was further enhanced to 54 mmol H2⋅L−1⋅h−1 by increasing reaction temperature, substrate, and enzyme concentrations—an increase of 67-fold compared with the initial studies using this method.
UT Austin researchers significantly boost yield and speed of lipids production from engineered yeast; more efficient biofuel production
March 24, 2015
Researchers in the Cockrell School of Engineering at The University of Texas at Austin have used a combination of metabolic engineering and directed evolution to develop a new strain of the yeast Yarrowia lipolytica featuring significantly enhanced lipids production that could lead to a more efficient biofuel production process. Their findings were published online in the journal Metabolic Engineering.
Beyond biofuels, the new yeast strain could be used in biochemical production to produce oleochemicals, chemicals traditionally derived from plant and animal fats and petroleum, which are used to make a variety of household products.
A*STAR team combines fungal culture and acid hydrolyses for cost-effective production of fermentable sugars from palm oil waste
March 16, 2015
After the harvest of the fruit from oil palm trees, large amounts of leftover biomass known as empty fruit bunch remain. The industry wants to use these leftover fruit bunches to produce bioethanol and biodegradable plastic, but has stumbled in their efforts to convert the leftovers in a cost-efficient way. The new fungal culture could make it possible to produce fermentable sugars from this huge amount of waste in a cost-effective way, thereby increasing its commercial value, said one of the lead researchers, Jin Chuan Wu, from the A*STAR Institute of Chemical and Engineering Sciences.
New engineered metabolic pathways in yeast enable efficient fermentation of xylose from biomass
March 05, 2015
Researchers with the Energy Biosciences Institute (EBI), a partnership that includes Berkeley Lab and the University of California (UC) Berkeley, have introduced new metabolic pathways from the fungus Neurospora crassa into the yeast Saccharomyces cerevisiae to increase the fermentative production of fuels and other chemicals from biomass. An open access paper on the work is publised in the journal eLife.
While S. cerevisiae is the industry mainstay for fermenting sugar from cornstarch and sugarcane into ethanol, it requires substantial engineering to ferment sugars derived from plant cell walls such as cellobiose and xylose. The new metabolic pathways enable the yeast to ferment sugars from both cellulose (glucose) and hemicellulose (xylose)—the two major families of sugar found in the plant cell wall—efficiently, without the need of environmentally harsh pre-treatments or expensive enzyme cocktails.
Researchers identify peptide to bind LMNO to improve power and performance of cathodes in Li-ion batteries
February 12, 2015
Researchers at the University of Maryland, Baltimore County (UMBC) have isolated a peptide, a type of biological molecule, which binds strongly to lithium manganese nickel oxide (LMNO), a material that can be used to make the cathode in high-performance Li-ion batteries. The peptide can latch onto nanosized particles of LMNO and connect them to conductive components of a battery electrode, improving the potential power and stability of the electrode.
The researchers presented their results at the 59th annual meeting of the Biophysical Society, held 7-11 Feb.in Baltimore, Maryland.
Engineered yeast produces ethanol from three important cellulosic biomass components simultaneously; higher yields, lower cost
February 11, 2015
A team led by researchers from the University of Illinois at Urbana−Champaign has, for the first time, integrated the fermentation pathways of both hexose and pentose sugars from biomass as well as an acetic acid reduction pathway into one strain of the yeast Saccharomyces cerevisiae using synthetic biology and metabolic engineering approaches.
The engineered strain co-utilized cellobiose, xylose, and acetic acid to produce ethanol with a substantially higher yield and productivity than the control strains. The results showed the unique synergistic effects of pathway coexpression, the team reported in a paper in the journal ACS Synthetic Biology.
Researchers use DNA to stabilize sulfur cathode for high-performance Li-sulfur batteries
February 10, 2015
|DNA has a high concentration of heteroatoms, including oxygen, nitrogen and phosphorus, that can anchor soluble polysulfides to improve the cycling performance of Li/S batteries. Li et al. Click to enlarge.|
A team from the China University of Geosciences has taken a novel approach to stabilizing Lithium-sulfur batteries by functionalizing the carbon-sulfur cathode with DNA.
Experimental results reported in a paper accepted for publication in the RSC Journal of Materials Chemistry A showed that adding a fine adding amount of DNA into a carbon/sulfur composite enables a significant improvement to cyclic performance by anchoring the soluble polysulfides that lead to performance degradation. The DNA-decorated electrode offered a discharge capacity of 771 mAh·g-1 at 0.1 C after 200 cycles (retention 70.7% of the initial)—a three-fold enhancement in capacity retention over 200 cycles.
Harvard hybrid “bionic leaf” converts solar energy to liquid fuel isopropanol
Scientists from a team spanning Harvard University’s Faculty of Arts and Sciences, Harvard Medical School and the Wyss Institute for Biologically Inspired Engineering at Harvard University have developed a scalable, integrated bioelectrochemical system that uses bacteria to convert solar energy into a liquid fuel. Their work integrates water-splitting catalysts comprising earth-abundant components with wild-type and engineered Ralstonia eutropha bacteria to generate biomass and isopropyl alcohol. An open access paper describing their work is published in Proceedings of the National Academy of Sciences (PNAS).
Pamela Silver, the Elliott T. and Onie H. Adams Professor of Biochemistry and Systems Biology at HMS and an author of the paper, calls the system a bionic leaf, a nod to the solar water-splitting artificial leaf invented by the paper’s senior author, Daniel Nocera, the Patterson Rockwood Professor of Energy at Harvard University. (Earlier post.)
Researchers discover bacteria could be rich source of terpenes
December 24, 2014
Researchers at Kitasato University in Japan, Brown University in the US, and colleagues in Japan have found that bacteria could be a rich source of terpenes—natural compounds common in plants and fungi that can be used to make drugs, food additives, perfumes, and other products, including advanced fuels (earlier post, earlier post).
Terpenes are responsible for the essential oils of plants and the resins of trees. Since the discovery of terpenes more than 150 years ago, scientists have isolated some 50,000 different terpene compounds derived from plants and fungi. Bacteria and other microorganisms are known to make terpenes too, but they’ve received much less study. The new research, published in an open access paper in the Proceedings of the National Academy of Sciences, shows that the genetic capacity of bacteria to make terpenes is widespread.
DOE JBEI team boosts methyl ketone production from E. coli 160-fold; advanced biofuel or blendstock
December 02, 2014
In 2012, researchers at the US Department of Energy’s Joint BioEnergy Institute (JBEI) engineered Escherichia coli (E. coli) bacteria to overproduce from glucose saturated and monounsaturated aliphatic methyl ketones in the C11 to C15 (diesel) range from glucose. In subsequent tests, these methyl ketones yielded high cetane numbers, making them promising candidates for the production of advanced biofuels or blendstocks. (Earlier post.)
Now, after further genetic modifications of the bacteria, they have managed to boost the E.coli’s methyl ketone production 160-fold. A paper describing this work is published in the journal Metabolic Engineering.
UCLA researchers develop synthetic biocatalytic pathway for more efficient conversion of methanol to longer-chain fuels
November 18, 2014
Researchers at the UCLA Henry Samueli School of Engineering and Applied Science led by Dr. James Liao have developed a more efficient way to turn methanol into useful chemicals, such as liquid fuels, and that would also reduce carbon dioxide emissions. The UCLA team constructed a synthetic biocatalytic pathway that efficiently converts methanol under room temperature and ambient atmospheric pressures to higher-chain alcohols or other higher carbon compounds without carbon loss or ATP expenditure.
Building off their previous work in creating a new synthetic metabolic pathway for breaking down glucose that could lead to a 50% increase in the production of biofuels (earlier post), the researchers modified the non-oxidative glycolysis pathway to utilize methanol instead of sugar. An open-access paper on the research was published in the 11 Nov. edition of the Proceedings of the National Academy of Sciences.
JBEI researchers boost isopentenol output from E. coli; potential benefit for bio-gasoline
October 27, 2014
Researchers at the US Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) have identified microbial genes that can improve both the tolerance and the production of isopentanol in engineered strains of Escherichia coli. Isopentenol is a five-carbon (C5) alcohol that is a highly promising candidate for biogasoline, but, like other short-chained alcohols, is toxic to E.coli at commercial levels of fuel production.
Aindrila Mukhopadhyay, a chemist who directs the host engineering program for JBEI’s Fuels Synthesis Division, led a study in which transcriptomic data and a synthetic metabolic pathway were used to identify several genes that not only improve tolerance but also production of isopentenol in E.coli. MetR, the methionine biosynthesis regulator, improved the titer for isopentenol production by 55%, while MdlB, the ABC transporter, facilitated a 12% improvement in isopentenol production.
Solazyme and Amyris receive Presidential Green Chemistry Challenge awards
October 16, 2014
The US Environmental Protection Agency (EPA) has announced the 5 winners of the 2014 Presidential Green Chemistry Challenge Awards, including biotechnology companies Amyris and Solazyme, Inc. Solazyme received the award for Greener Synthetic Pathways for its tailored oils produced from microalgal fermentation. Amyris received the Small Business award for its renewable hydrocarbon farnesane for use as diesel and jet fuel.
Amyris has engineered yeast to make the hydrocarbon farnesene via fermentation instead of ethanol. Farnesene is a building block hydrocarbon that can be converted into a renewable, drop-in replacement for petroleum diesel without certain drawbacks of first-generation biofuels. A recent lifecycle analysis estimated an 82% reduction in GHG emissions for farnesane, compared with the EPA baseline fossil diesel—including indirect effects.
BNL team devises new method to boost oil accumulation in plant leaves; implications for biofuel production
October 08, 2014
Researchers at DOE’s Brookhaven National Laboratory (BNL) have developed a new method to increase significantly the amount of oil accumulated in plant leaves, which could then serve as a source for biofuel production. Rather than adding genes, as some other research teams have done in their efforts to boost oil accumulation, the BNL method is based on is based on disabling or inactivating genes through simple mutations.
A series of detailed genetic studies revealed previously unknown biochemical details about plant metabolic pathways, including new ways to increase the accumulation of oil in leaves. Using these methods, the scientists grew experimental Arabidopsis plants (widely used as model organisms in plant biology), the leaves of which accumulated 9 wt % oil. This represented an approximately 150-fold increase in oil content compared to wild type leaves. A paper on their work is published in the journal The Plant Cell.
Researchers enhance yeast thermotolerance and ethanol tolerance; potential for significant impact on industrial biofuel production
October 03, 2014
The yeast Saccharomyces cerevisiae plays a central role in global biofuel production; currently, about 100 billion liters of ethanol are produced annually worldwide by fermentation of mainly sugarcane saccharose and corn starch by the yeast. There are also efforts underway to use the yeast with cellulosic biomass.
Boosting the yield and lowering the cost of fermentative production of biofuel would not only result in a significant immediate financial impact to commercial ethanol operations, but also support cost reductions that would be helpful to advance other advanced biofuels using the same or a similar pathway. However, boosting production has been gated by two key conditions: the ability of the yeast to tolerate higher temperatures, and the ability of the yeast to survive high concentrations of ethanol. Now, two new separate studies report progress on each of those fronts; the findings could have a significant impact on industrial biofuel production. Both papers are published in the current issue of the journal Science.
ARPA-E to award $60M to 2 programs: enhancing biomass yield and dry-cooling for thermoelectric power
October 02, 2014
|ARPA-E’s vision of advanced phenotyping to enhance biomass yield. Click to enlarge.|
The US Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E) will award up to $60 million to two new programs ($30 million each). The Transportation Energy Resources from Renewable Agriculture (TERRA) program (DE-FOA-0001211) seeks to accelerate biomass yield gains (especially energy sorghum) through automated, predictive and systems-level approaches to biofuel crop breeding. The Advanced Research In Dry cooling (ARID) program (DE-FOA-0001197) aims to develop low-cost, highly efficient and scalable dry-cooling technologies for thermoelectric power plants.
TERRA. ARPA-E posited that there is an urgent need to accelerate energy crop development for the production of renewable transportation fuels from biomass. While recent advances in technology has enabled the extraction of massive volumes of genetic, physiological, and environmental data from certain crops, the data still cannot be processed into the knowledge needed to predict crop performance in the field. This knowledge is required to improve the breeding development pipeline for energy crops.
German researchers boost algal hydrogen production five-fold using metabolic engineering approach
September 25, 2014
Scientists from the Max Planck Institutes for Chemical Energy Conversion and Coal Research and from the research group Photobiotechnology at Ruhr-Universität Bochum (RUB) have discovered a way of increasing the efficiency of hydrogen production in microalgae by a factor of five by using a combined metabolic engineering approach. An open access paper on their work is published in the RSC journal Energy & Environmental Science.
The genetic modifications resulting in the enhanced light-driven hydrogen production opens new avenues for the design of H2-producing organisms, which might lead to the design of an economically competitive hydrogen producing organism, the researchers suggest.
Researchers successfully engineer E. coli to produce renewable propane; proof-of-concept
September 03, 2014
Researchers from the University of Turku in Finland, Imperial College London and University College London have devised a synthetic metabolic pathway for producing renewable propane from engineered E. coli bacteria. Propane, which has an existing global market for applications including engine fuels and heating, is currently produced as a by-product during natural gas processing and petroleum refining. A paper on their work is published in Nature Communications.
The new pathway is based on a thioesterase specific for butyryl-acyl carrier protein (ACP), which allows native fatty acid biosynthesis of the Escherichia coli host to be redirected towards a synthetic alkane pathway. Although the initial yields were low, the team was able to identify and to add essential biochemical components in order to boost the biosynthesis reaction, enabling a the E. coli strain to increase propane yield, although the amounts are still far too low for commercialization.
DOE, USDA awarding $12.6M to 10 biomass genomics research projects for improved biofuels
July 17, 2014
The US Department of Energy (DOE) and the US Department of Agriculture (USDA) have selected 10 projects that will receive funding aimed at accelerating genetic breeding programs to improve plant feedstocks for the production of biofuels, biopower, and bio-based products.
The $12.6 million in research grants are awarded under a joint DOE-USDA program that began in 2006 focused on fundamental investigations of biomass genomics, with the aim of harnessing nonfood plant biomass for the production of fuels such as ethanol or renewable chemical feedstocks. Dedicated feedstock crops tend to require less intensive production practices and can grow on poorer quality land than food crops, making this a critical element in a strategy of sustainable biofuels production that avoids competition with crops grown for food.
Calysta reports 8-fold improvement in gas fermentation in ARPA-E program; BioGTL
July 10, 2014
Calysta, Inc. reported that it has achieved 8-fold improved performance over traditional fermentation technologies in a high mass transfer bioreactor. The bioreactor technology is under development for efficient methane-to-liquids fermentation processes, enabling rapid, cost-effective methane conversion into protein, industrial chemicals and fuels. (Earlier post.)
The improved performance was achieved in the research phase of a program funded in part by the Department of Energy’s ARPA-E program under the REMOTE program (Reducing Emissions using Methanotrophic Organisms for Transportation Energy), awarded in September 2013. (Earlier post.) Calysta develops sustainable industrial products using novel natural gas conversion technology using methane.
Joule first to gain US EPA clearance for commercial use of modified cyanobacteria for fuel production
July 01, 2014
The US Environmental Protection Agency (EPA) has favorably reviewed Joule’s Microbial Commercial Activity Notice (MCAN) for the company’s first commercial ethanol-producing catalyst (a modified Synechococcus cyanobacterium). This clears the catalyst for commercial use at the company’s demonstration plant in Hobbs, New Mexico.
This also marks the first time that EPA has allowed the commercial use of a modified cyanobacterium (although not of other modified microorganisms such as S. cerevisiae, E. coli, T. reesei, etc.). (The full list of EPA notifications under the Toxic Substances Control Act—TSCA—is available here.)
International team sequences Eucalyptus genome; potential for improving biofuel and biomaterial production
June 14, 2014
An international team of researchers has sequenced the genome of the eucalyptus tree (Eucalyptus grandis) and published the analysis in an open access paper in the journal Nature. With its prodigious growth habit, the eucalyptus tree, one of the world’s most widely planted hardwood trees, has the potential to enhance sustainable biofuels and biomaterials production, and to provide a stable year-round source of biomass that doesn’t compete with food crops.
The researchers reported the sequencing and assembly of more than 94% of the 640-megabase genome of Eucalyptus grandis. Of 36,376 predicted protein-coding genes, 34% occur in tandem duplications, the largest proportion thus far in plant genomes. Eucalyptus also shows the highest diversity of genes for specialized metabolites such as terpenes, which can be substituted catalytically for jet fuel.
Lux Research: cost of electrofuels remains far from viable
June 09, 2014
|Production costs per barrel of oil equivalent. Source: Lux Research. Click to enlarge.|
The cost of electrofuels—fuels produced by catalyst-based systems for light capture, water electrolysis, and catalytic conversion of carbon dioxide and hydrogen to liquid fuels—remains far away from viable, according to a new analysis by Lux Research.
Building a cost model for the electrolysis process—considering electricity from various routes, such as natural gas and coal as well as renewable electricity from biomass, solar, and wind, as well as generously assuming commercial scale production—Lux found that electrofuels produced from microbes cost $230 per barrel, while a catalytic conversion to make electrofuels produces fuels for $208 per barrel.
UGA-led team engineers bacterium for the direct conversion of unpretreated biomass to ethanol
June 03, 2014
A team led by Dr. Janet Westpheling at the University of Georgia has engineered the thermophilic, anaerobic, cellulolytic bacterium Caldicellulosiruptor bescii, which in the wild efficiently uses un-pretreated biomass—to produce ethanol from biomass without pre-treatment of the feedstock. A paper on the work is published in Proceedings of the National Academy of Sciences (PNAS).
In January, Dr. Westpheling and her colleagues reported in the journal Science their discovery that an enzyme (the cellulase CelA) from C. besciia can digest cellulose almost twice as fast as Cel7A, the current leading component cellulase enzyme on the market. (Earlier post.)
MSU microbial electrolysis cell produces ethanol from glycerol, reduces wastewater in biodiesel production
May 22, 2014
|The MEC uses syntrophic cooperation within a bacterial consortium (red and green) in the anode chamber to ferment ethanol from glycerol and to remove inhibiting H2. Credit: ACS, Speers et al. Click to enlarge.|
Researchers at Michigan State University have developed a microbial electrolysis cell (MEC) which will allow biodiesel plants to eliminate the creation of hazardous wastes while reducing their dependence on fossil fuel.
The platform, which uses microbes to produce ethanol from glycerol, has the added benefit of cleaning up the wastewater, will allow producers to reincorporate the ethanol and the water into the fuel-making process, said Gemma Reguera, MSU microbiologist and one of the co-authors. The ethanol replaces petrochemical methanol in the biodiesel production. A paper on their work is published in the ACS journal Environmental Science & Technology.