Scientists create cyborg bacteria to convert solar energy into useful chemicals

Researchers at the University of California (UC) Berkeley have created cyborg bacteria that can efficiently use solar energy to produce some useful chemicals. According to researchers, these bacteria can convert a mixture of cadmium and amino acid cysteine into a special type of nanoparticles, and by using these nanoparticles, they can convert solar energy into useful chemicals.

Chlorophyll is relatively inefficient in capturing sunlight

Plants are the primary source of food and energy for the most animal life on Earth. Plants create food with the help of photosynthesis process. In photosynthesis, green pigment chlorophyll absorbs the light from the Sun and converts it into energy. Carbon dioxide (CO2) and water are also used in this process.

While chlorophyll enables plants to create their own food, scientists believe chlorophyll is relatively inefficient in capturing sunlight, and we need to find more efficient ways to harvest the Sun’s light to fulfill our growing needs for energy.

In the past decades, many researchers have attempted to create artificial photosynthetic systems to convert sunlight into useful compounds, but most of them failed in their endeavor. The new research focuses on cyborg bacteria to harness sunlight and convert it into useful chemicals.

Moorella thermoacetica was fed with a mixture of cadmium and amino acid cysteine

In this study, UC researchers used Moorella thermoacetica, a nonphotosynthetic bacterium that consumes CO2 to produce Acetic Acid during respiration. Acetic acid is a versatile chemical and is generally used to make a variety of organic compounds and pharmaceuticals chemicals. UC researchers fed Moorella thermoacetica with a mixture of cadmium and amino acid cysteine, and were surprised to find that the bacteria converted this mixture into cadmium sulfide (CdS) nanoparticles.

According to researchers, CdS nanoparticles covered the bodies of Moorella thermoacetica. Researchers have named this hybrid organism as M-thermoacetica-CdS. It was also observed that these cyborg bacteria could easily produce acetic acid using sunlight, water, and CO2. Moreover, they demonstrated 80% efficiency in converting sunlight to energy—much higher than the 20% efficiency of chlorophyll.

According to researchers, the best part of this process is its self-replication, which makes it a zero-waste technology. Peidong Yang, a chemistry professor at uc berkeley, says his team is now working to find more benign light absorbers that could be used with these bacteria. Professor Yang says this technology has the potential to reduce high levels of CO2 from the atmosphere, and it could also help in reducing human reliance on fossil fuels.

This research was funded by the U.S. Department of Energy and the National Science Foundation, and its detailed findings were presented this week at the annual meeting of the American Chemical Society in Washington, D.C.