A solvent tolerant strain of Pseudomonas aeruginosa (PseA) was isolated from soil samples by cyclohexane enrichment in medium. The strain was able to sustain and grow in a wide range of organic solvents. The adaptation of P. aeruginosa cell towards solvents was seen at membrane level in transmission electron micrographs. It also secreted a novel protease, which exhibited remarkable solvent stability and retained most of the activity at least up to 10 days in the presence of hydrophobic organic solvents (log P >= 2.0) at 25% (v/v) concentrations. The protease was able to withstand as high as 75% concentration of solvents atleast up to 48 h. P. aeruginosa strain and its protease, both seem promising for solvent bioremediation, wastewater treatment and carrying out biotransformation in non-aqueous medium. (c) 2005 Elsevier Ltd. All rights reserved.