Winner of the Grand Prize at iGEM 2012 -> Food Warden - iGEM Groningen 2012 by iGEM Groningen 2012. The Food Warden is a system which detects meat spoilage. It uses Bacillus subtilis cells. Their natural genetic response to the gases of rotten meat has been identified and linked to a pigment production system. In this way, a consumer can easily see when the meat is spoiled: it's rotten and you know it!