Enterobacter cloacae are gram negative rods that form complex colonies known as biofilms. Cells in a biofilm are more resistant to antibiotics and disinfectants than planktonic cells. A bacterial isolate of Enterobacter cloacae from the 1989 water contamination in New Haven, CT, was used to study the genes involved in the production of capsule. Enterobacter cloacae were transformed with an EZ::TN < KAN2> Transposome and were selected for a decreased production of capsule as compared to the wild type. The genes yhjL, ksgA, cpxA, prc, rcsA, kpsT, man B, yojN, and galU were identified to be involved in the capsule production of Enterobacter cloacae by sequencing amplified PCR products using the RATE (Rapid Amplification of Transposon Ends) technique. Further research involving the genes identified in capsule production and their role in biofilm formation would provide prevention and treatment of biofilm formation in medical devices and water pipelines.