The British company ICI had a product called Pruteen, which was made by growing bacteria on methanol produced from natural gas as the energy source. It was intended as cattle feed; if people ate it there would be an excess of purines which could lead to gout.

Pruteen was followed by the more successful product Quorn, which is made from a fungus grown in fermentation tanks with glucose as the energy source. It is intended for human consumption as a meat substitute.