Breakthrough or No Breakthrough? As UK research team reports progress toward renewable propane, global media goes gaga

If you look this week in your Google News alerts, you’ll see an awful lot of breathless headlines around a meme something like “Researchers have engineered the harmless gut bacteria E.coli to generate renewable propane”. Reuters, Gizmodo, the UK’s Daily Telegraph, the massively distributed HuffPost, the Guardian, even stately NBC News have picked up the story.

And it’s great in a way — the science of the bioeconomy reaches major media. Woo-hoo! Too bad it’s four years late.

The newsfeeds all dial back to a spunky PR release that floated out on Science Daily on September 2nd, highlighting a new research effort in which a “team of scientists from Imperial College London and the University of Turku in Finland used Escherichia coli to interrupt the biological process…so that the bacteria made engine-ready renewable propane instead of cell membranes.”

In touting the new research results, Dr. Patrik Jones, from the Department of Life Sciences at Imperial College London said: “Although this research is at a very early stage, our proof of concept study provides a method for renewable production of a fuel that previously was only accessible from fossil reserves.

“Although we have only produced tiny amounts so far, the fuel we have produced is ready to be used in an engine straight away. This opens up possibilities for future sustainable production of renewable fuels that at first could complement, and thereafter replace fossil fuels like diesel, petrol, natural gas and jet fuel.”

Now, it certainly sounds exciting, and it would be if it were, um, true.

Are alkanes like propane really “only accessible from fossil fuels”?

Not really. The real breakthrough dates back to 2010. That’s when LS9’s research team in the Bay Area announced a breakthrough that demonstrated alkane production via e.coli at pilot scale.

In fact, you could have spotted it in Science magazine. That’s where we saw it. In the 2010 article “Microbial Biosynthesis of Alkanes,” a team of LS9 scientists announced the discovery of novel genes that, when expressed in E.coli, produce alkanes, the primary hydrocarbon components of gasoline, diesel and jet fuel.

LS9’s discovery was a big deal, then and now. It was the first description of the genes responsible for alkane biosynthesis and the first example of a single step conversion of sugar to fuel‐grade alkanes by an engineered microorganism.

At the time, LS9’s Vice President of Research and Development, Steve del Cardayre noted “This is a one step sugar‐ to‐diesel process that does not require elevated temperatures, high pressures, toxic inorganic catalysts, hydrogen or complex unit operations”.

But you could take it a little further, if you ignore the rate of production, and the overall yield — and why shouldn’t you? Everyone in mainstream media did.

As Wang, Liu and KLu observed last year in Biotechnology for Biofuels: “Alkanes with C4-C23 carbon chain length… can be produced by various organisms such as bacteria, yeasts, plants and insects…In the late 1960s, production of alka(e)nes was reported in a diversity of cyanobacteria.”

The problem is not that there aren’t organic ways to produce propane. There are scads of ways to produce alkanes at something like 0.1% of cell weight. The problem is: well, not to repeat ourselves — but how about “rate, titer and yield”?.

The problem with alkanes is that no known organism produces enough naturally make a process economically viable. Improving on nature? That work has been going on for quite a while.

Back to fuel school: What’s an alkane again?

Alkanes include methane (one carbon atom), ethane (C-2), propane (C-3), butane (C-4), pentane (C-5), octane (C-8) and all the way up to an array of C-12, C-32 and even C-60 types, or isomers. Broadly they are also known as the paraffins. Butane and propane are commonly known as LPG, or liquid petroleum gas. The middle alkanes, from pentane to octane, are among the usual suspects in gasoline, while the higher alkanes, from C-9s up to C-16, are the usual suspects in diesel and aviation fuel.

The R&D backgrounder

For over 20 years scientists have tried to identify the genes that enable particular natural organisms to directly convert biomass into alkanes. However, previous scientific research has failed to identify these genes. To solve this mystery, the LS9 team looked into the genomes of bacteria that produce alkanes in nature known as cyanobacteria.

“We evaluated many cyanobacteria that made alkanes and identified one that was not capable of producing them. By comparing the genome sequences of the producing and non‐producing organisms, we were able to identify the responsible genes,” said Andreas Schirmer, Associate Director of Metabolic Engineering at LS9.

Where’s the LS9 IP these days?

REG locked it all up in an acquisition of LS9 last year — and it all currently resides within the business unit known as REG Life Sciences.

So, what’s different in this new research out of the EU?

The research team is clearly pointing towards a photosynthetic process — which is to say, that ultimately the feedstock source materials would be sunlight, CO2 and water. That’s different, since LS9’s process uses sugar, and is heterotrophic.

Another focal point in this research effort from the EU — the propane target. That’s highly specific, and will be more valuable going forward. Our fossil source of propane is, to a great extent, wet natural gas. And, globally, while gas is being discovered all over the world, insiders whisper “yeah, but it drying up” – meaning more low-value methane and less high-value ethane and propane.

One other difference in this new research effort — they are targeting a temperature range which would gasify the propane — immensely simplifying the harvest and extraction procedure. Instead of the costly and complex separation technologies associated with, say, algae.

The cautionary note

Ah Grasshopper, you’ve learned your Digestology well if you’ve waited to read this paragraph before launching the celebrations.

The researchers warn:

“The level of propane that the scientists produced is currently one thousand times less than what would be needed to turn it into a commercial product, so they are now working on refining their newly designed synthetic process.”

Dr Jones said: “At the moment, we don’t have a full grasp of exactly how the fuel molecules are made, so we are now trying to find out exactly how this process unfolds. I hope that over the next 5-10 years we will be able to achieve commercially viable processes that will sustainably fuel our energy demands.” Meaning, check back in this space, somewhere between 2019 and 2024.

The Bottom Line

Bottom line, it’s exciting stuff, high potential. But about as far out as a mission to the asteroid belt. There’s real merit in this line of research — particularly in terms of the target — though we don’t know nearly enough about potential rate, titer or yield to get as excited about it as the Huffington Post clearly is.

And we have to say — the subscription department at Science magazine really ought to pay some calls on major media — could be a goldmine for them in back issues.