Simpler peptidoglycan chemical composition in the highly transformant Escherichia coli DH5 alpha strain

Artificial transformation of Escherichia coli is obtainable by treating the culture with CA2+ and other substances known to increase the permeability of the outer membrane. Nevertheless, particular strains of E. coli are more useful for transformation since the number of transformants obtained is far higher. We postulate that an additional layer of the envelope may play an important role comparable to that of the outer membrane. The chemical composition of the peptidoglycan of a highly efficient transformant E. coli strain (DH5 alpha) was analyzed in comparison with a normal and poorly transformant E. coli strain (KN126) revealing a simpler peptidoglycan chemical composition in the DH5 alpha strain. This may be responsible for the simpler architecture of the peptidoglycan which, in turn, may interfere less with the passage of the DNA across the bacterial envelope.