Solar panels grown in cyborg bacteria

Researchers in California have turned microbes into solar generators.

The development of photosynthesis in cyanobacteria was a pivotal moment in the evolution of life. But photosynthesis itself is a pretty inefficient process. Around the world, scientists are trying to improve it through bioengineering.

Now researchers from the University of California, Berkeley (UCB), have induced bacteria to coat themselves in tiny, highly efficient solar panels.

The scientists used a species called Moorella thermoacetica, which does not naturally photosynthesise, but lead researcher Kelsey Sakimoto and his colleagues induced them to cover themselves in semiconductor nanocrystals.

The work follows some by UCB’S Peidong Yang, who specialises in making inorganic semiconductors and binding them to bacteria.

Sakimoto chose M. thermoacetica because it produces acetic acid in its normal respiratory cycle. The acid is used to create polymers and other products.

The researchers successfully induced the bacteria to bond with a combination of cadmium and the amino acid cysteine – which contains a sulfur atom, causing the bacteria to synthesise cadmium sulfide (CDS) nanoparticles – which function as solar panels. The resulting hybrids – dubbed M. thermoacetica-cds – produced acetic acid using CO , water and light at 2 80% efficiency.

“Rather than rely on inefficient chlorophyll to harvest sunlight, I’ve taught bacteria how to grow and cover their bodies with tiny semiconductor nanocrystals,” Sakimoto says.

“These nanocrystals are much more efficient than chlorophyll and can be grown at a fraction of the cost of manufactured solar panels.”