Biologists train microbes to make biofuel

A team of biologists and engineers modified a microbe called

Rhodopseudomonas palustris to produce a biofuel using only three renewable and naturally abundant source ingredients: Carbon dioxide, solar panel-generated electricity and light.

The resulting biofuel, n-butanol, is an authentically carbon-neutral fuel alternative that can be used in blends with diesel or gasoline.

The fuel they made, n-butanol, has a high energy content and low tendency to vaporize or dissolve in water without combustion.

Microbes that feed through microbial electrosynthesis (MES) reactor, attach themselves directly to a negatively charged cathode inside the reactor so that they can "eat" electricity.

To explore how microbe could be exploited to produce biofuel, they constructed a mutant form of the microbe that could not fix Nitrogen. The scientists then introduced an artificial n-butanol biosynthesis pathway into this new mutant.

The form of the microbe they built was unable to grow when Nitrogen gas was its only Nitrogen source. So instead, this version of microbe channelled its effort into producing n-butanol—increasing its yield of biofuel without increasing electricity consumption significantly.

Industrial-scale manufacturing of bioplastics and biofuels using microbial electrosynthesis can be achieved using the electricity produced by solar panels, creating a fully sustainable cycle.