General Information: Isolated from a biofilm from San Diego Bay in California. Marine biofilm bacterium associated with shell disease in shellfish. A common marine bacterium that exists both in the water column, and in biofilms attached to surfaces. This organism produces a well characterized, commercially important agarase. Pseudoalteromonas atlantica has been isolated from lesions on crabs with shell disease. Shell disease is characterized by progressive degradation of the shell, often leading to an infection of the hemolymph (blood) and may be caused by Pseudoalteromonas, Alteromonas, Vibrio, or other marine organisms. In addition to producing extracellular enzymes which attack the shell, Pseudoalteromonas atlantica produces a the lipopolysaccharide which has been shown to be a potential virulence factor in shell disease.