Fire blight is a contagious disease affecting apples and pears caused by the bacterium Erwinia amylovora. For bacteria to cause disease, they must produce amylovoran, a protective exopolysaccharide secreted by the bacteria to its environment. We are isolating mutant strains of E. amylovora that have altered amylovoran levels to discover novel genes that may be involved in amylovoran production. Preliminary results show a correlation between bacterial amylovoran production and disease in immature apples.