A principal problem in the production of biofuel, one of the chief emerging alternatives to fossil fuels, is that the complicated process requires the use of multiple containers across production, breaking down the efficiency of the process.
Recently however, as described in a study published in Green Chemistry, researchers at the US Department of Energy’s Lawrence Berkeley National Laboratory have successfully engineered a strain of bacteria that will enable the production of biofuel to be carried out in a single pot.
This is a significant step because it could enable biofuels to finally compete with traditional fossil fuels, which can be manufactured in fewer steps and with less management.
The study builds on previous research conducted at the Joint BioEnergy Institute that remedied the difficulties of using ionic liquids, which worked efficiently to break down the plant structures but were harmful to the enzymes used in order to produce the actual biofuel.
In 2012, JBEI researchers, including Blake Simmons, a co-author on this paper, discovered a suite of saccharification enzymes that were tolerant to ionic liquids, creating a foundation for the process that the new study’s first author, Marijke Frederix, was able to build on in order to engineer an E.coli strain that was highly tolerant to ionic liquids.
According to Frederix, “armed with the rcdA variant, we were able to engineer a strain of E. coli that could not only tolerate ionic liquid, but that could also produce ionic-liquid-tolerant enzymes that chew up the cellulose, make sugars, eat it and make biofuels.
“E. coli remains the workhorse microbial host in synthetic biology, and in our study, using the ionic-liquid-tolerant E. coli strain, we can combine many earlier discoveries to create an advanced biofuel in a single pot.”
Beyond the common products of this process, such as ethanol, researchers are looking to get more out of biofuel and push the process to new areas.
In this case, they used production models already established at the JBEI to create d-limonene, a precursor to jetfuel. The ability to do so, aided by the streamlined process enabled by the new “one-pot” method, shows that biofuel, and those involved in its production, is moving ever closer to its goal of competing with fossil fuels as a fully viable, commercial energy source.
As said by the study’s prinicpal investigator and vice president of the Fuels Synthesis Division at the JBEI, Aindrila Mukhopadhyay: “Being able to put everything together at one point, walk away, come back, and then get your fuel, is a necessary step in moving forward with a biofuel economy.
“The E. coli we’ve developed gets us closer to that goal. It is like a chassis that we build other things onto, like the chassis of a car. It can be used to integrate multiple recent technologies to convert a renewable carbon source like switchgrass to an advanced jet fuel.”