Figure 6.

Anthranilamide is required for the biosynthesis of actinomycins L₁ and L₂. Box plots show the relative intensities of actinomycin L₁ and L₂ after log transformation and pareto scaling in the cultures of Streptomyces sp. MBT27 (a) and S. antibioticus (b) fermented for 7 days in MM with fructose (1% w/v) (1), fed with 0.7 mM anthranilamide (2) and 0.7 mM anthranilic acid (3). Note that S. antibioticus produces actinomycin L exclusively in the presence of anthranilamide and not with anthranilic acid; conversely, Streptomyces sp. MBT27 is able to convert anthranilic acid into anthranilamide, enabling the production of actinomycin L.