Biofuels are a potential way to help the environment because they produce less carbon dioxide than fossil fuels, and they’re sustainable. Unfortunately, the process by which they are made can be inefficient.
Biofuels are a byproduct of bacteria eating such things as corn or sugarcane, from which they get necessary nitrogen. The problem is that there are other invasive strains of bacteria that can get into fermentation vats and outcompete the original bacteria, resulting in the creation of less biofuel than expected.
However, a team of researchers at MIT has developed a system called ROBUST, which features genetically engineered bacteria to produce biofuels. These bacteria are able to get nitrogen from unconventional sources that “wild” microbes couldn’t process.
The researchers created microbes that can use compounds such as melamine to feed the biomass, said Gregory Stephanopoulos, the Willard Henry Dow Professor of Chemical Engineering and Biotechnology at MIT. Melamine is a xenobiotic, or artificial, chemical that contains 67 percent nitrogen by weight.
The result is bacterial strains that manage to vastly outperform invasive microbes, meaning more biofuel is produced.
“By engineering the strains to make them capable of utilizing these unconventional sources of phosphorous and nitrogen, we give them an advantage that allows them to outcompete any other microbes that may invade the fermenter without sterilization,” Stephanopoulos says.
There are other ways of dealing with the invasive microbes, but they aren’t as efficient or as cost effective. One is steam sterilization, which requires more expensive vats for the fermentation process. The other involves antibiotics to target the invasive microbes. However, antibiotics are expensive and bacteria evolve quickly, meaning they can become immune to antibiotics with astonishing speed.
The new ROBUST system, however, is cheaper than either option and doesn’t contribute to the creation of antibiotic-resistant “superbugs.” These things combined could mean a bright future for biofuels and for the planet.