In this paper, we reported a kind of exoelectrogens. Pseudomonas alcaliphila (P. alcaliphila) strain MBR. which could excrete phenazine-1-carboxylic acid (PCA) to transfer electron under alkaline condition in microbial fuel cells (MFCs). The electrochemical activity of strain MBR and the extracellular electron transfer mechanism in MFCs were evaluated by cyclic voltammetry (CV) and electricity generation curve measurement. The results indicated a soluble mediator was the key factor for extracellular electron transfer of strain MBR under alkaline condition. The soluble mediator was PCA detected by gas chromatography-mass (GC-MS) analyses. (C) 2011 Elsevier Ltd. All rights reserved.