 Similarly, phenazine-1-carboxylic acid, produced by a number of Pseudomonas, increases survival in soil environments and has been shown to be essential for the biological control activity of certain strains.Phenazine biosynthesis branches off the shikimic acid pathway at a point subsequent to chorismic acid.Two molecules of this chorismate-derived intermediate are then brought together in a diagonally-symmetrical fashion to form the basic phenazine scaffold.