Serratia marcescens grows at 37°C, but it can grow in temperatures that range from 5–40°C. They grow in pH levels that range from 5 to 9. Serratia marcescens is well known for the red pigmentation it produces called prodigiosin. Prodigiosin is made up of three pyrrole rings and is not produced at 37°C, but at temperatures below 30°