[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.]
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.
Researchers engineer poplar trees for easier degradation of lignin to ease production of biofuels
April 04, 2014
|Poplar vascular tissue showing feruloyl-coenzyme A (CoA) monolignol transferase (FMT) expression. Source: GLBRC. Click to enlarge.|
Researchers from Michigan State University and the University of Wisconsin-Madison and their colleagues report successfully engineering poplar trees to produce lignin that degrades more easily, thereby lowering the effort and cost to convert wood to biofuel. A paper on their work appears in the journal Science.
Poplar trees are a fast-growing wood crop widely planted throughout the United States and Canada, and are particularly valuable to the bioenergy, bio-products, and fiber industries. Lignin provides strength to wood but also impedes efficient degradation when wood is used as feedstock for biofuel. The researchers identified an enzyme (coniferyl ferulate feruloyl-CoA monolignol transferase) in other plants that contain more digestible lignin monomers, then expressed it in poplar. The resulting trees showed no difference in growth habit under greenhouse conditions, but their lignin showed improved digestibility.
Synthetic biology company launches JV to commercialize gas-to-liquids bioconversion; isobutanol first target
March 28, 2014
Synthetic biology company Intrexon Corporation has formed Intrexon Energy Partners (IEP), a joint venture with a group of external investors, to optimize and to scale-up Intrexon’s gas-to-liquids (GTL) bioconversion platform. IEP’s first target product is isobutanol for gasoline blending.
Intrexon’s natural gas upgrading program is targeting the development of an engineered microbial cell line for industrial-scale bioconversion of natural gas to chemicals, lubricants and fuels, as opposed to employing standard chemical routes. Intrexon says it has already achieved initial proof of concept with an engineered microbial host converting methane into isobutanol in a laboratory-scale bioreactor.
Scientists synthesize first functional designer chromosome in yeast
An international team of scientists led by Dr. Jef Boeke, director of NYU Langone Medical Center’s Institute for Systems Genetics, has synthesized the first functional chromosome in yeast, an important step in the emerging field of synthetic biology—designing microorganisms to produce novel medicines, raw materials for food, and biofuels. A paper on the accomplishment is published in the journal Science.
Over the last five years, scientists have built bacterial chromosomes and viral DNA, but this is the first report of an entire eukaryotic chromosome built from scratch. Researchers say their team’s global effort also marks one of the most significant advances in yeast genetics since 1996, when scientists initially mapped out yeast’s entire DNA code, or genetic blueprint.
Lawrence Livermore, JBEI researchers engineer bacteria with tolerance to ionic liquids for enhanced production of advanced biofuels
March 26, 2014
Researchers from Lawrence Livermore National Laboratory in conjunction with the Joint BioEnergy Institute (JBEI) have engineered tolerance to ionic liquids (ILs)—used for biomass pretreatment, but generally toxic to bacteria—into biofuel-producing bacteria.
The results, reported in an open access paper in Nature Communications are likely to eliminate a bottleneck in JBEI’s biofuels production strategy, which relies on ionic liquid pretreatment of cellulosic biomass. The research also demonstrates how the adverse effects of ionic liquids can be turned into an advantage, by inhibiting the growth of other bacteria.
Siluria Technologies unveils new development unit for liquid fuels from natural gas based on OCM and ETL technologies
March 21, 2014
Siluria Technologies, the developer of novel bio-templated catalysts for the economic direct conversion of methane (CH4) to ethylene (C2H4) (earlier post), unveiled a development unit for producing liquid fuels from natural gas based on Siluria’s proprietary oxidative coupling of methane (OCM) and ethylene-to-liquid (ETL) technologies.
Together, Siluria’s OCM and ETL technologies form a unique and efficient process for transforming methane into gasoline, diesel, jet fuel and other liquid fuels. Unlike the high-temperature, high-pressure cracking processes employed today to produce fuels and chemicals, Siluria’s process employs catalytic processes to create longer-chain, higher-value materials, thereby significantly reducing operating costs and capital.
Renewable Energy Group acquires drop-in renewable fuels company LS9 for up to $61.5 million
January 24, 2014
Biodiesel producer Renewable Energy Group, Inc. (REG) has acquired LS9, Inc., a synthetic biology company developing fermentation-derived drop-in renewable fuels and chemicals (earlier post), for a purchase price of up to $61.5 million, consisting of up front and earnout payments, in stock and cash. Most of the LS9 team, including the entire R&D leadership group, will join the newly named REG Life Sciences, LLC, which will operate out of LS9’s headquarters in South San Francisco, CA.
Under the terms of the agreement, REG paid $15.3 million in cash and issued 2.2 million shares of REG common stock (valued at approximately $24.7 million based on a trading average for REG stock) at closing. In addition, REG may pay up to $21.5 million in cash and/or shares of REG common stock consideration for achievement of certain milestones over the next five years related to the development and commercialization of products from LS9’s technology.
U Texas at Austin researchers rewire yeast for high lipid generation; 60x improvement over parent strains
January 21, 2014
Researchers at the University of Texas at Austin’s Cockrell School of Engineering have rewired the native metabolism of the yeast Yarrowia lipolytica for superior production of lipids (lipogenesis). Tri-level metabolic control resulted in saturated cells containing upwards of 90% lipid content and titres exceeding 25 g l−1 lipids—a 60-fold improvement over parental strain and conditions.
In the study, reported in the journal Nature Communications, the researchers genetically modified Y. lipolytica by both removing and overexpressing specific genes that influence lipid production. In addition, the team identified optimum culturing conditions that differ from standard conditions.
DEINOVE produces ethanol at 9% titer with its optimized Deinococcus bacteria
January 16, 2014
DEINOVE, a technology company that designs, develops and markets a new generation of industrial processes based on optimized Deinococci bacteria, has produced ethanol at a titer of 9% via its fermentation of biomass sugars in 20L pre-industrial fermentors. In September 2012, the company had reported that its optimized strain of Deinococcus generated ethanol from wheat-based biomass with a titer of 3%. (Earlier post.)
The 9% content v/v (volume/volume)—equal to 7.2% wt/v (weight/volume)—exceeds the 5% alcohol content wt/v considered to be the threshold for industrial exploitation of a process for 2nd generation biofuels, the company said. The obtained performance is gradually approaching the maximum theoretical yield, the company added. The use of Deinoccoccus offers several benefits:
Berkeley Lab-led team re-engineering new enzyme and metabolic cycle for direct production of liquid transportation fuels from methane
A Berkeley Lab-led team is working to re-engineer an enzyme for the efficient conversion of methane to liquid hydrocarbon transportation fuels. The project was awarded $3.5 million by the Advanced Research Projects Agency - Energy (ARPA-E) as part of its REMOTE (Reducing Emissions using Methanotrophic Organisms for Transportation Energy) program. (Earlier post.)
Methane can be converted to liquid hydrocarbons by thermochemical processes; however, these processes are both energy intensive and often non-selective. There are bacteria in nature—methanotrophs—that consume methane and convert it to chemicals that can be fashioned into fuel. Unfortunately, the enabling enzyme doesn’t produce chemicals with the efficiency needed to make transportation fuels. While some scientists are working to make this enzyme more efficient, Dr. Christer Jansson’s team is taking a new approach by starting with a different enzyme that ordinarily takes in carbon dioxide.
Field trials with genetically modified poplars shows potential for efficient conversion to sugars but with impact on biomass yield
December 31, 2013
|Ethanol yield (g/L) for the Belgian and French field trials. Van Acker et al. Click to enlarge.|
The results of field trials with genetically modified poplar trees in Belgium and France shows that the wood of the modified poplar trees—down-regulated for cinnamoyl-CoA reductase (CCR), an enzyme in the lignin biosynthetic pathway—improved saccharification yield—i.e., it can be more efficiently converted into sugars for producing bio-based products such as bio-plastics and bio-ethanol.
However, the study, published as an open access paper in Proceedings of the National Academy of Sciences (PNAS), also found that strong down-regulation of CCR also affected biomass yield. The team, from Belgium, France and the US, led by researchers from VIB and Ghent University, concluded that CCR down-regulation may become a successful strategy to improve biomass processing if the yield penalty can be overcome.
USDA and DOE award $8.1M to 7 biomass genomics research projects for biofuel and bioenergy
December 12, 2013
The Department of Energy’s Office of Science, Office of Biological and Environmental Research (DOE-BER), and the US Department of Agriculture National Institute of Food and Agriculture’s Agriculture and Food Research Initiative (USDA-NIFA) are jointly awarding $8.1 million in research grants to 7 projects using genomics to develop non-food feedstocks that can be used for bioenergy. The awards continue a commitment by the two agencies begun in 2006 to conduct fundamental research in biomass genomics that will establish a scientific foundation to facilitate and accelerate the use of woody plant tissue for bioenergy and biofuel. (Earlier post.)
In 2013, DOE will provide $6.1 million in funding over 3 years, while USDA will award $2 million over 3 years. Overall, the USDA and DOE projects are designed to improve biomass—including selected trees and grasses—to be grown for biofuels by increasing their yield, quality and ability to adapt to extreme environments. Researchers will rely on the most advanced techniques of modern genomics to develop breeding and other strategies to improve the crops. The research will be conducted on switchgrass, poplar and pine, among other plants.
Mascoma bioengineered yeasts have produced more than 1B gallons of ethanol
December 11, 2013
Mascoma Corporation, a leading provider of bioconversion technology, announced that its consolidated bioprocessing technology (CBP) has been used to produce more than 1 billion gallons of corn ethanol. The company said that this represented a key commercial milestone for its MGT yeast products including TransFerm and TransFerm Yield+. (Earlier post.)
Using its proprietary CBP technology platform, Mascoma has developed bioengineered yeasts to reduce costs and improve yields in the production of renewable fuels and chemicals. Mascoma’s first commercial application of its technology platform are its Mascoma Grain Technology (MGT) yeast products, which are drop-in substitutes for existing yeasts designed to improve the economics of corn-based ethanol production.
Venter: algae biofuels require “real scientific breakthroughs”; biofuels need a carbon tax to be viable
During his keynote and subsequent question-and-answer session at the BIO Pacific Rim Summit on Industrial Biotechnology and Bioenergy in San Diego this week, Dr. Craig Venter, Founder, Chairman, and CEO, J. Craig Venter Institute and Founder and CEO, Synthetic Genomics, Inc. (SGI) tangentially provided a brief update on the status of SGI’s research work with ExxonMobil into algae biofuels, as well as some general observations on the prospects for algae biofuels.
“As far as I know, the same experiment has been done over and over again for the last 50 years. To my knowledge, not one single group has achieved higher lipid levels than you can get out of natural occurring algae. For it to be economically viable we need at least five times that rate. … In my view, we need some real scientific breakthroughs that change what algae can do,” said Dr. Venter.
DSM and DONG Inbicon show cellulosic bio-ethanol fermentation on industrial scale with 40% higher yield
December 09, 2013
Royal DSM, together with DONG Energy (Denmark), has demonstrated the combined fermentation of C6 and C5 sugars from wheat straw on an industrial scale. The combined fermentation results in a 40% increase in ethanol yield per ton of straw, which can result in significant cost cuts in the production of bio-ethanol from cellulosic feedstock.
The demonstration took place in DONG Energy’s Inbicon demonstration plant in Kalundborg (Denmark), the longest running demonstration facility for cellulosic bio-ethanol production in the world. (Earlier post.) The facility was reconstructed in 2013 in order to be able to conduct mixed fermentation of C6 and C5 sugars. In a two-month fermentation test mixed C6 and C5 fermentation using DSM’s advanced yeast was found to yield 40% more ethanol per ton of straw than traditional C6 fermentation.
Amyris and Total form joint venture to produce and market renewable diesel and jet fuel
December 05, 2013
Amyris, Inc. and Total have formed Total Amyris BioSolutions B.V., a 50-50 joint venture that now holds exclusive rights and a license under Amyris’s intellectual property to produce and market renewable diesel and jet fuel from Amyris’s renewable farnesene. (Earlier post.) Total is Amyris’ largest investor, holding approximately 18% of its outstanding common stock, and is committed to the development of next-generation renewable fuels from biomass.
Amyris’ synthetic biology platform enables the modification of the genetic pathways of microorganisms, primarily yeast, to turn them into living factories to produce target molecules via fermentation. The primary biological pathway within the microbe Amyris currently uses to produce target molecules is the isoprenoid pathway.