Bacteria could feed the world. While some bacteria turn CO2 into valuable fuels, other bacteria – called ‘hydrogenotrophs’ – can transform CO2 into proteins suitable for human consumption.
In a sense, this shouldn’t come as a great surprise. The plants we eat, or that we feed to livestock, grow because they take energy from the Sun and use it to convert CO2 into carbohydrates. Strictly speaking, plants didn’t evolve this ability to transform CO2 into food: they gained the skill by incorporating photosynthetic bacteria into their cells.
Solar panels are more effective than photosynthetic organisms at capturing solar energy, and this raises an intriguing possibility. If we can take solar electricity and use it to help bacteria build protein from CO2, we could grow food more efficiently than ever before.
Solar Foods, a Finnish start-up, is one of several companies aiming to commercialism this non-photosynthetic food. Dr Pasi Vainikka, the company’s CEO, says the approach involves using power from solar panels to break down water molecules and generate hydrogen gas.
Solar Foods then feeds the hydrogen to bacteria growing in a fermenter – for commercial reasons Vainikka prefers not to reveal exactly what species of hydrogenotroph this is. The microbes use this hydrogen as an energy source to turn atmospheric CO2 into high-quality protein that could replace animal proteins in our diet.