Transduction of citrate-utilization genes into Escherichia coli K12.

Genes for citrate utilization were transferred by transduction into Escherichia coli from Salmonella and Klebsiella strains. The genes appear to take chromosomal positions at 6-10 min on the K12 linkage map. Growth on citrate medium by Cit+ K12 hybrids was poor. Incorporate of glycine or L-serine into citrate minimal media improved growth of K12 Cit+ hybrids on citrate. The significance of these findings is discussed.