Solar panels for yeast cell biofactories

Genetically engineered microbes such as bacteria and yeasts have long been used as living factories to produce drugs and fine chemicals. More recently, researchers have started to combine bacteria with semiconductor technology that, similar to solar panels on the roof of a house, harvests energy from light and, when coupled to the microbes' surface, can boost their biosynthetic potential. 

The first "biological-inorganic hybrid systems" (biohybrids) mostly focused on the fixation of atmospheric carbon dioxide and the production of alternative energies, and although promising, they also revealed key challenges. For example, semiconductors, which are made from toxic metals, thus far are assembled directly on bacterial cells and often harm them in the process. In addition, the initial focus on carbon-fixing microbes has limited the range of products to relatively simple molecules; if biohybrids could be created based on microorganisms equipped with more complex metabolisms, it would open new paths for the production of a much larger range of chemicals useful for many applications.

"While our strategy conceptually builds on earlier bacterial biohybrid systems that were engineered by our collaborator Daniel Nocera and others, we expanded the concept to yeast – an organism that is already an industrial workhorse and is genetically easy to manipulate – with a modular semiconductor component that provides biochemical energy to yeast's metabolic machinery without being toxic," said Joshi, Ph.D., who is a Core Faculty member at the Wyss Institute and Associate Professor at SEAS.