Hemingway’s Cats and Tobacco Road

February 29, 2012 |

Even while sleeping, one of Hemingway's cats displays his six-toed paw

New ideas on growing hydrocarbons directly in the field tap ancient ideas of agriculture, and ancient capabilities trapped deep in the genome

Funky, eclectic Key West was once the home to much of the US Navy’s Caribbean squadron and, in the 19th century, at the forefront of national security worries, based on the threat expressed by colonial French, Danish, English, Spanish and Dutch forces operating in the region.

Between 1931 and 1939, Key West was also home to Ernest Hemingway, who penned some of his best-known works there, including A Farewell to Arms and To Have and Have Not.

His legacy in Key West includes a brood of around 50 cats, descended from his own, that continue to inhabit what is known as Hemingway House. About half the cats have additional toes, one of them a total of 26, instead of a cat’s usual assemblage of 18.

Advantages resident in the genome

Cats with this feature were highly prized by sea captains in days gone by, because their fearsome multi-toed climbing and stalking skills made them astonishingly effective rat catchers; it was a sea captain that gave Hemingway his first polydactyl cats.

Today, the cats’ multi-toed features make them more of a curiosity than rat-catching machines, but they serve to remind us, in visual ways that microbes cannot easily signify to us, that inside the genetic code of any organism, large or small, there is an untapped universe of possibility.

And it reminds us that sometimes the best way to improve a process – rat-catching or otherwise – is not to develop a new technology, based on layers of human invention and intervention, but simply to improve the old one that required no human intervention at all. Why invest in rat poison, when you can simply improve the cat?

They do their magic for their own purposes (cats don’t chase rats for your benefit, but their own) but sometimes, as Tom Sawyer famously discovered in the Mark Twain novel, there’s nothing sweeter in life than to complete a chore by getting your friends to whitewash a fence for you. Or getting cats, corn or even cyanobacteria to do the work.

Beyond frankenplants and frankenfoods

To critics, genetic transformation is a world gone wrong – of frankenplants, frankenfoods or frankenalgae – to be greeted with OMG!!! or choruses of “Run for your lives!”, as if genetics can only serve us up variations from creature-feature horror films of the 1950s.

They point to the insertion of genes from a breed of cold-tolerant fish into the tomato’s genetic code, to produce a cold-resistant tomato, a fishmato that forms a new base for quite a lot of the modern tomato crop we know and eat.

But Hemingway’s cats remind us that not all changes are so radical, and not every modificationb results in some thing that you are likely to eat.

A good part of the work of modern genetics is to uncover the existing possibilities within the existing genome, which after all is like a series of lights in a house, some switched on and others switched off – each combination producing a slight variation. Whether it is multi-toed cats, or salt-tolerant, pest-resistant or drought tolerant crops – much of the work of modern crop development and yield improvement lies in discovering and liberating features already in the plant.

Over at ARPA-E, new thinking in what crops can do

This week in Washington, some of the most advanced thinking in the nexus of energy and agriculture are under discussion at the ARPA-E Summit in Washington.

Two major themes have emerged what ARPA-E and others are funding, at the bleeding edge of energy crop development. Both are aimed at utilizing the unique ability of plants to grow biomass by drawing together a series of simple molecules and tapping a source of energy.

In the plant world, there are highly complex processes by which they do their work, but in the end, plants and microbes take carbon dioxide, water and energy source (typically, sunlight energy – although some microbes take their energy from consuming biomass itself – such as the heterotrophic algae used by Solazyme and Phycal). From these, they make carbohydrates.

One theme of modern R&D focuses on the fact that, while plants are very, very good at making biomass – they are not very efficient at using sunlight. 1-3 percent of photon energy is captured and used, ultimately by plants; by contrast, a solar panel system can capture between 10 and 20 percent of the sun’s energy in making electricity, and solar science is expected to do even better in the future.

The electrofuels

Could a system be created that uses a solar panel’s efficiency at capturing energy and converting it to electricity, with the ability of microbes and plants to make a range of useful molecules? Armed with the knowledge that there are forms of bacteria that can utilize electricity as an energy source, ARPA-E developed what is called the Electrofuels series of projects.

Ultimately, the goal is to marry inorganic systems (by which solar panels are powered) with organic systems (that make useful ranges on molecules, instead of just a stream of electrons). There’s more on the electrofuels, here, in our recent wrap-up: “When Bio and Solar converge.”

Growing hydrocarbons in the field

Another stream of R&D is even more near-term in its application to bioenergy. Why not, goes the reasoning, engineer a plant in the field to directly make hydrocarbons, or enzymes that reside in the plant? As opposed to harvesting a crop, then using fermentation or thermochemical conversion to produce a fuel molecule – why not build a process right into the plant?

Agrivida is one company building enzymes into the plant itself – which are activated when processing begins.  Syngenta’s Enogen technology builds a corn amylase enzyme into the corn kernel itself, also liberated and activated when processing of the corn begins.

In the case of Agrivida or Enogen technology, the advantage is in the elimination of a separate and costly process for growing enzymes – and possibly the cost of transporting them to the processing plant. The enzymes are delivered right inside the crop.

An even more far-out technology is based on work at Lawrence Berkeley National Lab in Berkeley, California. A $4.9 million ARPA-E project led by LBL scientist Christer Jansson. The goal? To engineer tobacco plants to directly produce hydrocarbon fuel molecules, which are them retrieved from the plant, when it is crushed for processing – no need for conversion at all – simply a matter of growing hydrocarbons, and harvesting. Just as we have grown and harvested carbohydrates, lipids and proteins since time immemorial.

On Tobacco Road

They chose tobacco because it is a relatively easily-modified plant, as genetic engineering goes, and it is widely grown and can be harvested several times a year,

As we known from companies like LS9, select microorganisms have the capability to produce alkanes, which are drop-in fuel hydrocarbons. In the ARPA-E funded research, the team will develop synthetic, tobacco-friendly versions of these genes, insert them into tobacco plants, and then refine the metabolic pathways as they spot any bottlenecks.

The research team believes that an acre of tobacco could produce as much as 1,000 gallons of drop-in, hydrocarbon fuels.

Who would have thought that tobacco, widely considered a demon leaf because of the carcinogenic results experiences by heavy tobacco smokers – might prove to be the first platform for growing hydrocarbon fuels directly in the fields?

If the LBL team realizes its goals, there is something fitting in all this. Tobacco was America’s original cash crop – and Virginia’s first economy was based on it, and a great number of the country’s founding fathers, including Washington and Jefferson, were tobacco planters.

Why not indeed use qualities already resident in the plant to revolutionize our ideas about how we create transportation fuel – by returning to the oldest idea that powers human civilization, the principles of grow, harvest, crush and use.

More on the LBL project, funded by ARPA-E, here
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