8 Hot Targets in Advanced Bioeconomy R&D

by Jim Lane (Biofuels Digest) Fuels, chemicals, pathways, and microbes that could shake it all up ... (H)ere 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.

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.

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.

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.

“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.”

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.

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.

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.

We’ve written quite a bit about the opportunities for high-value, high-density renewable aviation fuels using the terpenes.

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