8 Hot Targets in Advanced Bioeconomy R&D

May 27, 2015 |

7 Hot TargetsFuels, chemicals, pathways, and microbes that could shake it all up

This week, we’ll be visiting with the Lords of Biofuels Creation at the annual retreat of the Joint BioEnergy Institute in California, which have issued an NDA the length of a Bible as a condition of admission. So we are skeptical we will be able to report in detail on the latest from Silicon Valley, so in the meanwhile, here are 8 Hot Targets that we can point to that could be game-changers in the world of making fuels, chemicals and biomaterials from pleasant alternatives to petroleum.

The one you’ll note that is missing is the opportunities in depolymerizing lignin. We are hopeful to include significant progress on that front in a future update.

1. Nanocellulose

It’s been around for a long time, but the science has advanced quite a bit in the past 18 months. We may be on the verge of a commercial breakthrough in these materials, which have “great potential as a strength enhancer in paper, as additives in composites, in emulsions, as oxygen barriers for food packaging and in biomedical devices.

It’s been described as “the Next World-Changing Supermaterial” in a Gizmodo piece that warned “Watch out, graphene” and described it as the “kevlar-strength, super-light, greenhouse gas-eating nanomaterial of the future.”

As a team led by UT’s Malcolm Brown reported last year: “Nanocellulose-based materials can be stronger than steel and stiffer than Kevlar. Great strength, light weight and other advantages has fostered interest in using it in everything from lightweight armor and ballistic glass to wound dressings and scaffolds for growing replacement organs for transplantation.”

Brown’s lab team reported an amazing breakthrough last year — what could be a scalable process to make nanocellulose using sunlight and water via genetically-enhanced cyanobacteria, borrowing genes from Acetobacter xylinum — a bacterium best known for making vinegar, but also for secreting nanocellulose.

As American Process CEO Theodora Retsina explained in the Digest last year:

“The market potential for nanocellulose is vast. The USDA estimates that the short-term market is over 34 million tons per year.  Nanocellulose can replace and/or complement plastics, oil and fracking drilling fluid, emulsifiers and has many other applications. It can be used to strengthen and reduce the weight of automotive components, contributing to overall vehicle fuel efficiency. And it is renewable, compostable, biocompatible and abundant.”

We reported on the latest in nanocellulose here, and here and here’s a link to the Global Nanocellulose Market report which has production volumes, total, forecasted and by producer for nanocellulose applications in composites, electronics, construction, paper and pulp, filtration, medicine and life sciences, paints, films, coatings, rheological modifiers, aerogels and oil industry — it includes commercialization timelines, by market as well as producer, research centre and application developer profiles.

The complete Global Nanocellulose Market report is available here .

2. Return of the Native (feedstock). Hemp makes a comeback.

Cast aside years ago generally owing to the potential for visual confusion between marijuana and industrial hemp, with the rise of legalization of cannabis, hemp is also making quite a comeback.

As one story on the newswires this week indicated:

“As more U.S. states loosen their policies on recreational and medical marijuana operations, companies are racing to become the industry leaders in cultivation technology for growing cannabis and hemp industry innovators.  Cannabis Companies in focus today are Surna Inc. (OTC: SRNA), Green Grow Technologies Inc. (OTC: GRNH), Medical Marijuana Inc. (OTC: MJNA), Totally Hemp Crazy Inc. (OTC: THCZ), Pazoo, Inc. (OTC: PZOO) and Terra Tech Corp.  (OTC: TRTC)”

We observed last year:

We first started tracking hemp back in 2009, when a 43-acre biomass trial launched in California that features hemp as a feedstock. The notoriety of hemp’s cousin, marijuana, has created both passionate supporters and opponents of the feedstock, which for centuries provided useful by-products such as rope, but acquired a massive brand identity problem after reefer acquired wide popularity as a recreational drug.

Bottom line, hemp is a non-food crop that grows on infertile land and does not have psychoactive properties like its cousin the cannabis plant. It’s one of a family of plants that provide what are known as “bast fibers”. Bast is the barrier material between the bark and the inner woody material (the “xylem”) of plants like flax, hemp, jute, kenaf, and even stinging nettle.

For many years, these were the primary material in Europe for making cloth — and tales like Hans Christian Andersen’s The Wild Swans include scenes of young heroines spinning cloth out of stinging nettles. Though hemp fell into disfavor and outright bans because of its association with marijuana, it’s been making a comeback in the fiber world.

In fact, Naturally Advanced Technologies entered into a development and supply agreement with Target in 2011 evaluate the use of its CRAiLAR Flax fiber in Target’s domestic textiles category. The proprietary CRAiLAR enzymatic process turns natural bast fibersinto soft, finished textiles and can be integrated with existing technology for spinning, weaving, or forming fabric.

So, there’s medical (or recreational) hemp and industrial hemp — not the same thing. There’s also a crop known as sunn hemp, a legume that has nothing to do with either.

Bottom line, it’s perhaps the feedstock with the longest history of useful applications for which we haven’t seen a titanic amount work on crop and yield development. Which makes it a highly pportune target for development.

More on the story.

3. Targeting RuBisCo improvement

You might wonder why most terrestrial plants have low photosynthetic efficiencies — many in the sub 2% region. Which brings us to the problem child, Rubisco, or by its full name ribulose-1,5-bisphosphate carboxylase oxygenase. Though obscure to the average citizen, it is not at all uncommon; in fact, it is the most abundant protein on earth.

It’s role: it is the enzyme that catalyzes the first step in the fixation of atmospheric carbon (for most plants, and also for cyanobacteria). Though abundant, RuBisCo is a slow, dim-witted enzyme if ever there was one. So slow that it fixes just three carbon molecules per second, and so dim-witted that it has trouble distinguishing between oxygen and CO2. Under many conditions, it will fix oxygen instead of CO2, in a process called plant respiration which causes carbon loss and robs the plant of growth opportunity.

As an article in Nature recently observed:

“Researchers have long wanted to increase yields by targeting Rubisco, the enzyme responsible for converting carbon dioxide into sugar. Rubisco is possibly the most abundant protein on Earth, and can account for up to half of all the soluble protein found in a leaf. But one reason for its abundance is its inefficiency: plants produce so much Rubisco in part to compensate for its slow catalysis. Some have estimated that tinkering with Rubisco and ways to boost the concentration of carbon dioxide around it could generate up to a 60% increase in the yields of crops such as rice and wheat.”

So, what’s new?

As Nature observes:

“A team including Hanson and plant physiologist Martin Parry of Rothamsted Research in Harpenden, UK, shuttled bacterial Rubisco genes into the genome of the chloroplast — the cellular organelle where photosynthesis takes place — in the tobacco plant (Nicotiana tabacum), a common model organism for genetic-engineering research. In some of the plants the researchers also added a bacterial protein that is thought to help Rubisco to fold properly. In others, they added a bacterial protein that structurally supports Rubisco.

Both lines of tobacco were able to use the bacterial Rubisco for photosynthesis, and both converted CO2 to sugar faster than normal tobacco.”

The Bottom Line. Keep an eye on RuBisCo research and, in general, the search for increased photosythetic efficiency. Should efficiencies rise to the 10 percent range, a tremendous number of conflicts over land allocayion simply melt away.

More on the story.

4. Electrofuels

In general, these are organisms, generally bacteria, that use surplus electricity produced from solar and wind or other renewable energy sources to convert CO2 into biomaterials and biofuels. So, it’s a photosynthesis bypass. Natural bacteria exists which can convert CO2 into methane and acetate but researchers believe with some small genetic mutations they can get the bacteria to produce fuel.

As ARPA-E’s Electrofuels manifesto states:

“Most biofuels are produced from plant material that is created through photosynthesis, a process that converts solar energy into stored chemical energy in plants. However, photosynthesis is an inefficient process, and the energy stored in plant material requires significant processing to produce biofuels. Current biofuel production methods are also intensive and require additional resources, such as water, fertilizer, and large areas of land to grow crops. Electrofuels bypass photosynthesis altogether by utilizing microorganisms that are self-reliant and don’t need solar energy to grow or produce biofuels. These microorganisms can directly use energy from electricity and chemical compounds like hydrogen to produce liquid fuels from carbon dioxide (CO2).”

Here’s one recent project from Denmark.

An example: The UCLA electrofuels program

UCLA is utilizing renewable electricity to power direct liquid fuel production in genetically engineered Ralstonia eutropha bacteria. UCLA is using renewable electricity to convert carbon dioxide into formic acid, a liquid soluble compound that delivers both carbon and energy to the bacteria. The bacteria are genetically engineered to convert the formic acid into liquid fuel—in this case alcohols such as butanol.

Current limitations of electrofuels technology

Well, right now they are all of them in the lab. But more importantly, at truly massive scale there is going to be a requirement for drop-in fuels, as opposed to alcohols that don’t readily blend at high levels and meet EPA and vehicle specs.

Right now, most electrofuels magic bugs have been engineered to produce higher alcohols – generally isobutanol, although Harvard’s Wyss Institute is investigating octanol. Others are looking at bio-oils that will need further upgrading to drop-in fuels.

A lonely alternative – aimed at drop-in fuels? Ginkgo BioWorks has a project to produce isooctane – now, that’s in the gasoline range (and has a terrific 100 octane rating – in fact, its the baseline gasoline component for “octane ratings” that measure anti-knock properties).

One other limitation? Water. At scale, the systems will likely need to be based on seawater, or at least brackish non-potable water, or even water recovered from fossil wellhead areas. No point in solving the biomass problem to get right back into a freshwater sustainability problem.

Here are the entire class of 13 electrofuels projects funded by ARPA-E.

5. Artificial photosynthesis.

OK, so you don’t like the outcomes from traditional photosynthesis, you don’t like bypassing it with electrofuels — so what’s a good scientist to do? Invent a new system of photosynthesis from the ground up. Which, essentially, is the case with a team of DOE, Berkeley Lab and UC-Berkeley researchers who: “have created a hybrid system of semiconducting nanowires and bacteria that mimics the natural photosynthetic process by which plants use the energy in sunlight to synthesize carbohydrates from carbon dioxide and water.

Researcher Chris Chang noted:

“In natural photosynthesis, leaves harvest solar energy and carbon dioxide is reduced and combined with water for the synthesis of molecular products that form biomass. In our system, nanowires harvest solar energy and deliver electrons to bacteria, where carbon dioxide is reduced and combined with water for the synthesis of a variety of targeted, value-added chemical products.”

So, the nanowire forest does the work of capturing sunlight, and the organisms use the electrons to catalyze the production of acetete from water and carbon dioxide.

Game-changer? Could be. It’s a technology  that can capture carbon dioxide emissions before they are vented into the atmosphere and then, powered by solar energy, convert that carbon dioxide into valuable chemical products, including biodegradable plastics, pharmaceutical drugs and even liquid fuels.

Researcher Peidong Yang pointed to a “forest” of nanowires that substitute for functinos fround in terrestrial plants. “Our artificial forest is similar to the chloroplasts in green plants,” Yang says. “When sunlight is absorbed, photo-excited electron−hole pairs are generated in the silicon and titanium oxide nanowires, which absorb different regions of the solar spectrum.” Once the nanowire forest is built, microbes are added that catalyze

Limitation? “This new artificial photosynthetic system synthesizes the combination of carbon dioxide and water into acetate — which is to say, a precursor for many things but we don’t have a one-step pathway to a transfomraiyon energy molecule.

We highlighted the research here.

6. Fuel cell breakthroughs

OK, so for some reason you simply want to bypass biomass strategies altogether — after all, what you want at the end of the day is a fuel molecule that works in a known propulsion technology, and you’d like to get it from something abundant like water, if you could.

So, what about fuel cell technologies, in which you convert hydrogen to water (using abundant atmospheric oxygen), and in the process you create a release of chemical energy — a technology Toyota is getting way, way down the road with via its line of fuel cell vehicles.  You can learn about the revolutionary Toyota Mirai here.

Limitation on that technology? First, you need a new vehicle and second, the world needs a new fueling infrastructure in the form of delivering hydrogen to you, cost effectively and (we hope) renewably.

So here’s a breakthrough on the fuel side. What about splitting water to make hydrogen in the first place? Now, you might think – here’s a perpetual energy machine, splitting water into hydrogen and oxygen and then recombining it. But in this case, we could be using solar energy to split water — so we are consuming energy to make this reaction work, but we are using free, abundant solar energy. To us, this is the ultimate technology — no land use, no carbon, little net water usage, an all renewable source of energy, a proven vehicle technology that provides range and power.

It really does address just about every societal need. Except one. It’s not here yet, and there’s a series of major technological hurdles. As Stanford’s National Accelerator Lab notes:

The bottleneck for the efficiency of electrochemical and photoelectrochemical water splitting is the high overpotential required for the anodic half-reaction, the oxygen evolution reaction (OER). In contrast to many other catalytic reactions, e.g. in fuel cells, where thorough fundamental understanding of the interactions at the atomic scale that determine catalytic activity and catalyst stability in a corrosive environment has been achieved, such understanding, which could lead to breakthrough discoveries of new materials with significantly enhanced catalytic performance, is still lacking for the OER. – See more here.

One Center focused on the opportunities of solar fuels — and which just picked up $75 million for five more years from DOE, is the Joint Center on Advanced Photosynthesis. They note:

We still lack sufficient knowledge to design solar-fuel generation systems with the required efficiency, scalability, and sustainability to be economically viable. JCAP seeks to discover new ways to produce energy-dense fuels, such as hydrogen and carbon-based fuels, using only sunlight, water, and carbon dioxide as inputs.  Artificial photosynthesis, once achieved and scaled up, could be significantly more efficient than biofuel production processes and would not require arable land, agricultural feedstock, or substantial inputs of energy or water.  

Bottom line – it’s early days, but watch this technology. It’s really a matter of delivering an affordable technology for onboard splitting of water into hydrogen and oxygen as fast as a fuel cell can use the hydrogen. It needs to be fast — because otherwise you need to carry around massive amounts of oxygen (which is 90% of the weight of water) to capture the hydrogen for the fuel cell. And, you need to have a very small net water usgae, which means efficient recapture, otherwise you have to stop and refill all the time. The rest of it is FCV technology, which has moved along very nicely.

7. Terpenes as advanced fuels for aviation.

We’ve written quite a bit about the opportunities for high-value, high-density renewable aviation fuels using the terpenes. As a team of researchers from the Naval Air Warfare Center at China Lake and NIST, headed by Dr. Ben Harvey, observed a few months back in a journal article we summarized here:

“Renewable fuels with densities that exceed those of conventional jet fuels by up to 13% can be generated from multicyclic sesquiterpenes. This advance has the potential to improve the range of aircraft, ships, and ground vehicles without altering engine configurations. In addition, as strategies to efficiently convert lignocellulosic biomass into sugars improve and organisms are developed that can utilize these sugar mixtures and convert them to sesquiterpenes, these fuels can be produced on a scale that would help supplant significant quantities of petroleum.”

The latest? Sabinene was the subject of a recnt study repotted in Microbial Cell Facotories. Zhang et all reported:

“In this study, sabinene was significantly produced by assembling a biosynthetic pathway using the methylerythritol 4-phosphate (MEP) or heterologous mevalonate (MVA) pathway combining the GPP and sabinene synthase genes in an engineered Escherichia coli strain…This is the first report of microbial synthesis of sabinene using an engineered E. coli strain with the renewable carbon source as feedstock. Therefore, a green and sustainable production strategy has been established for sabinene.”

This bit stood out for us:

“The sabinene titer of strain HB4 reached 44.74 mg/L after being induced by 0.25 mM IPTG for 24 h with glycerol as carbon source and beef powder as nitrogen source (Figure  3B). The titer was about 20-fold higher than that of the strain HB3 cultured at the same conditions…These results indicated that the hybrid MVA pathway caused a huge increase in sabinene production, which was accordant with the production of other terpenes using a hybrid exogenous MVA pathway in engineered E. coli strains.”

Another candidate? Bisabolene. In 2011, we highlighted that JBEI was seeking industry partners interested in licensing its technologies. In “Alternative Diesel Fuel from Biosynthetic Bisabolene” JBEI researchers had produced a chemical precursor that readily converts to bisabolane, a plant-derived hydrocarbon chemically related to turpentine that can deliver comparable performance to standard D2 diesel fuel.

In 2013, we noted that researchers at Lawrence Berkeley National Labs developed a new technology that enables the engineering of host microorganisms suitable for biofuel processing using ionic liquid pretreatment. Laboratory tests indicated that an engineered strain of E. coli carrying the IL-tolerance genes was able to grow and produce the fuel precursor, bisabolene, in the presence of 4% 1-ethyl-3-methylimidazolium chloride.

And last year, JBEI reported that mapping “ the terpene biosynthetic pathway in a model actinobacterium, Streptomyces venezuelae, and further alter secondary metabolism to afford the advanced biofuel precursor bisabolene. Leveraging information gained from study of the native isoprenoid pathway, we were able to increase bisabolene titer nearly 5-fold over the base production strain, more than 2 orders of magnitude greater than the combined terpene yield in the wild-type host. We also explored production on carbon sources of varying complexity to, notably, define this host as one able to perform consolidated bioprocessing.”

More on the story, here.

8. Promising molecules for diesel fuels

What’s up on the diesel side? One of the most interesting developments this year has been work at JBEI on methyl ketones. A team of researchers led by Herry Beller reported a 160-fold increase in  E.coli’s methyl ketone production rate — to 40% of theoretical.

Read more here. 

Geller added:

“We’re encouraged that we could make such a large improvement in methyl ketone production with a relatively small number of genetic modifications,” says Harry Beller, a JBEI microbiologist who led this study. “We believe we can further improve production using the knowledge gained from in vitro studies of our novel metabolic pathway.”

“In our original effort, for methyl ketone production we made two major modifications to E. coli,” Beller says. “First we modified specific steps in beta-oxidation, the metabolic pathway that E. coli uses to break down fatty acids, and then we increased the expression of a native E. coli enzyme called FadM. These two modifications combined to greatly enhance the production of methyl ketones.”

“Although the improved production is still not at a commercial level in the biofuel market, it is near a commercial level for use in flavor and fragrances, where certain methyl ketones are much more highly valued than they would be in the biofuel market. It may be possible for a company to sell a small percentage of methyl ketones in the flavor and fragrance market and use the profits to enhance the economic viability of the production of methyl ketones as biofuels.”

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