Abstract
Phenazines are secondary metabolites chiefly known for their broad-spectrum anti-microbial property. Phenazine-1-carboxylic acid (PCA) produced by Pseudomonas aeruginosa, a gram-negative bacterium, is an effective biocontrol agent against a number of plant-related pathogens. This experiment aimed to increase the production of PCA by deleting genes UTR, phzM and phzS in Pseudomonas aeruginosa M18, thus rendering the new strain more suitable for commercial use. The triple-deleted mutant M18ΔUMS shows significantly increased performance in PCA production compared to wild-type M18 strain. The new strain should be more applicable for commercial usage. However, M18ΔUMS exhibits a decreased growth rate compared to M18, indicating a inhibitory effect caused by the excess PCA.