Researchers in Canada have published a proof-of-concept report showing the potential for using E. coli to create biogenic photovoltaic cells.
Some bacteria photosynthesize sunlight into energy the same way plants do. In this study, researchers genetically-engineered E. coli to over-produce photosynthesizing enzymes. Then they coated those cells with nanoparticles of titanium dioxide and spread the coated cells on a glass surface.
The result was that "[t]he cells had a current density of 0.686 milliamperes per square centimeter, twice that of similar biogenic solar cells others have previously made. The efficiency with which they converted light to electricity remained the same under bright and dim light conditions."
That may be the most exciting result. If successful, these biogenic cells could generate energy from the sun even in places with little sunlight, such as in far northern and southern latitudes and in the deep sea.
You can read the study here.