(Lumen Bioscience) Mesfin Gewe, senior scientist at Lumen Bioscience in Seattle, holds a dish filled with powdered spirulina cells. To target methane gas, the spirulina are engineered to express the lysin protein. Lysin can be added to cattle feed to break down methane-causing bacteria, called “methanogens.” Once in a cow's stomach, the protein will destroy the methanogen microbes, a process that results in less climate-damaging methane gas released into the atmosphere by cows.