I have only half-jokingly commented before that the ideal microorganism for energy production would consume garbage and excrete gasoline, which would float to the top of a reactor to be skimmed off via a low-energy process. Technically, there isn’t any reason that this shouldn’t be feasible. It’s just a matter of understanding the metabolic pathways, and successfully doing the genetic engineering. But to put that into perspective, it is probably also technically feasible to engineer humans to use photosynthesis for energy, or to engineer a blueberry tree. In other words, technically feasible is often a long way from imminently doable.
But there has been a flurry of stories this week about another venture backed by Vinod Khosla called LS9 which bills itself as the renewable petroleum company and is promising something not too far from what I have described above. A story this week by David Roberts of Gristmill captures the highlights:
The process is the same as making cellulosic ethanol insofar as cellulosic feedstocks are converted into fermentable sugars, and those sugars are placed in a fermentation vat. The difference comes in the microbes doing the fermenting. With ethanol, it’s generally some form of yeast. The researchers at LS9 have engineered their own microbes, lifting genes from other microbes and recombining them into an organism that does just what they want. In this way they can precisely tweak the characteristics of the resulting fuel.
Yeast fermentation produces ethanol, which mixes with water and subsequently has to be extracted via distillation. LS9’s microbes produce — via fatty acid metabolism, in a process I won’t claim to understand — hydrocarbons (the building blocks of petroleum). These hydrocarbons are immiscible, i.e., they don’t mix with water. Instead, they float to the top of the vat, where they can essentially be skimmed off. That allows LS9 to skip the distillation process, which saves a whole boatload of energy. (That’s where most of the claimed 65% energy savings comes from.)
There is certainly no reason to think that this isn’t technically feasible. After all, the human body produces fatty acids that have a chemical structure that involves long-chain hydrocarbons. It is not far-fetched to accept that organisms can be engineered to produce very specific hydrocarbons. And I do think this is a much better approach than producing ethanol that requires an energy intensive distillation to remove the water.
Can you be more concise?
Sure. LS9 has genetically engineered microbes that will eat sugar and crap oil.
Naturally, this all piqued my interest. Since several news releases referred to “patents pending”, I went and searched the United States Patent Office for published applications. After an hour of searching, I came up empty. But, that’s not necessarily a negative indicator. I have had patents that took a while to work their way through the process. It just means that it is harder to understand whether there is more hype here than warranted, because the technical details aren’t in the public record. I wrote to LS9, and they responded back immediately and said 1). They read this blog; and 2). No, their applications aren’t yet published.
So, thwarted on that front, I started looking through their web site in search of 1). Advertised job openings; and 2). The specific skill set of the team they have in place. Both of these things can tell you a lot. If they are advertising for a lot of public relations types and are skimpy on looking for scientists and engineers, then my suspicion is raised. Likewise if they are very generic about available openings. But, they did have specific advertised openings for those sorts of technical positions. So I view that as a positive.
On the second item, the background of the team can tell you a lot. In order to have a good chance at success, I would expect that they are putting together a team knowledgeable about specific metabolic pathways for microorganisms. I found that. Again, as soon as their web site is back online, I will be more specific.
At this stage, I see no reason to doubt their claims, but you essentially have to take them at their word. But I give very good odds that even if they don’t pull this off, someone will. I will try to update this story as more information comes out.
A bit of additional reading:
Producing hydrocarbon fuels is more efficient than producing ethanol, del Cardayre adds [Stephen del Carayre, VP for R&D], because the former packs about 30 percent more energy per gallon. And it takes less energy to produce, too. The ethanol produced by yeast needs to be distilled to remove the water, so ethanol production requires 65 percent more energy than hydrocarbon production does.
At least they have their facts in order. Of course all of those who insist that it is more energy efficient to produce ethanol than gasoline aren’t going to like that.