A phenazine-1-carboxylic acid (PCA)-degrading bacterium, strain DP58, was isolated from pimiento rhizosoil. Based on morphology, physiologic tests, 16S rDNA sequence, and phylogenetic characteristics, it was identified as Sphingomonas sp. The PCA-degradation experiments were conducted both in Luria-Bertani and inorganic salt medium at 28 degrees C. The relationship between bacterium growth and PCA degradation suggested that strain DP58 could use PCA as the sole source of carbon and nitrogen and was able to completely degrade PCA in 40 hours. Newly isolated strain DP58 represents the first bacterium that can degrade PCA.