Incompatibility of Citrate Utilization Plasmids Isolated from Escherichia coli

Abstract
The 57 conjugative Cit plasmids isolated from 72 citrate-utilizing (Cit+) Escherichia coli strains from various sources were classified into four groups on the basis of their genetic properties. Escherichia coli K12 strains carrying these Cit plasmids could utilize cis-aconitate or tricarballylate. in addition to citrate.