Leuconostoc is a genus of gram-positive bacteria, placed within the family of Leuconostocaceae. They are generally ovoid cocci that often form chains. Leuconostoc strains are linked to a few negative aspects, including spoilage in the sugar cane industry and food products by the formation of slime, and safety as they have been identified in human clinical isolates. However, the history of human exposure and consumption has led to the conclusion that Leuconostoc is a microorganism generally regarded as safe.