backtop


Print 18 comment(s) - last by shaidorsai.. on Jun 30 at 9:52 AM


  (Source: ksj.mit.edu)
E. coli was used to make fatty acids of the correct length

A biofuel that acts similar to gasoline minus the carbon dioxide seems like an ideal solution to staying green, keeping current vehicles relevant and the dwindling oil supply -- and researchers may have found the first steps toward that direction. 

Harvard University researchers -- led by Pamela Silver, Ph.D., a Wyss Institute Core Faculty member and Professor of Systems Biology at Harvard Medical School -- have engineered bacteria to make precursors of high-octane biofuels to potentially replace gasoline. 

The problem with gasoline is that its oil supply is running low, and gives off large amounts of carbon dioxide. But gasoline isn't all bad -- it can produce a lot of energy when burned in an internal combustion engine, and it stays in a liquid form no matter the temperature. 

This is where many of today's biofuels go wrong. They nix the carbon dioxide, but can't produce the power that gas can in an internal combustion engine. In fact, they produce only two-thirds of the energy gasoline can. Also, ethanol-packed fuels can corrode pipes and tanks normally used for gasoline. Between these two reasons, biofuel use would make a majority of today's vehicles (with internal combustion engines) irrelevant. 

That's where Harvard's new study comes in. Using E. coli to make fatty acids, which are gasoline precursors, the team ended up with energetic molecules of carbon and hydrogen atoms. These chains were about 4-12 carbons long, because anything shorter wouldn't pack enough energy for fuels and anything longer would be "waxy." Oil refineries make medium-length chains too, but use petroleum while this study used living organisms. 

The team then adjusted a metabolic pathway for E. coli that creates fatty acids. The pathway allows carbon from sugar to flow, and as it flows, it grows longer. It eventually leaves as a long-chain fatty acid. They then genetically altered an enzyme that typically allows for long-chain fatty acids so that it would only allow eight-carbon chains.

They also tried blocking the flow of carbons using a drug that blocks certain enzymes, which are responsible for extending fatty acid chains. This caused medium-length chains (which the team wanted) to pool up behind the barrier. But some of the carbons could still pass by to build membranes. 
In the end, the team mass-produced an eight-carbon fatty acid called octanoate. This can be converted into octane.

This study was published in Proceedings of the National Academy of Sciences.

Source: Eurekalert



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

Nice, but...
By Motoman on 6/26/2013 5:55:46 PM , Rating: 2
This is great and all, but the important question ultimately is whether or not you can efficiently create the fuel without adversely affecting some other important system.

Which is to say, are we going to get a net gain in energy potential with the resulting fuel, or does it take as much energy to make it as you get out of it, like with many ethanol processes? And is it going to interact with the food supply, or anything else of importance...like, for instance, do we need to "feed" it with something?




RE: Nice, but...
By ShieTar on 6/27/2013 5:46:12 AM , Rating: 2
You need to feed it indeed. It is a post-processing of sugar (as is very briefly mentioned in the article above). It is no completely new idea, but rather a different process of producing a bio-fuel with a higher energy density.

Therefore, the overall impact on the global energy-equation gets higher as you loose some additional processing energy, but it increases the range of a car with a fixed tank-size.


RE: Nice, but...
By cyberguyz on 6/27/2013 10:46:04 AM , Rating: 2
Do you have a viable, renewable alternative?

We would love to hear it and the environmental impact studies you have done around it.


RE: Nice, but...
By Motoman on 6/27/2013 12:30:26 PM , Rating: 2
No...and my question is whether or not this one is either.

To date, it doesn't seem like *anything* is a viable alternative.

My guess is that long-term maybe some kind of biodiesel becomes viable. I don't really see any ethanol processes ever being valid.


RE: Nice, but...
By Ramstark on 6/27/2013 3:07:41 PM , Rating: 2
I think that the process should be aimed at engineering bacteria that use as "fuel" some type of inorganic trash or residue from another process, that way, we would have the "affected process" solved.

I wonder, which process has sugar as a subproduct or residue?


RE: Nice, but...
By Motoman on 6/27/2013 3:59:56 PM , Rating: 2
If any existing processes have sugar, or something close thereto, as an unwanted output, I can guarantee you that it's already spoken for.


"Mac OS X is like living in a farmhouse in the country with no locks, and Windows is living in a house with bars on the windows in the bad part of town." -- Charlie Miller

Related Articles













botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki