INDUCTION OF PHENAZINE BIOSYNTHESIS IN CULTURES OF PSEUDOMONAS-AERUGINOSA BY L-N-(3-OXOHEXANOYL)HOMOSERINE LACTONE

A range of Pseudomonas spp. and other Gram-negative bacteria were-scre ened for induction of antimicrobial activity in response to the autore gulatory factor L-N-(3-oxohexanoyl)homoserine lactone. In one of these , P. aeruginosa ATCC 10145, the production of phenazine metabolites wa s shown to be inducible in a dose-dependent manner. The production of phenazine-1-carboxamide increased over 50-fold compared to control cul tures when supplemented with 200 mu g/ml of the autoregulator. In addi tion, the production of an unidentified polar antibacterial substance by this strain increased with autoregulator concentration.