Evaluation of protease stability from Pseudomonas aeroginosa strain PTCC1430 in organic solvents

Aim and Proteases have multiple applications within organic media, and then their organic solvent stability is critically important. Pseudomonas aeruginosa elastase is an organic solvent stable enzyme. In the present work, following protein purification, its organic solvent activity and stability have been investigated. Protein purification was carried out by affinity chromatography. Enzyme activity within organic solvent media has been measured by activity measurements in the 0-70% (V/V) of organic solvents including ethanol, methanol, isopropanol, dimethyl formamide (DMF), glycerol and ethylene glycol. In the presence of all concentrations of organic solvents investigated in the present study, except ethanol, activity of elastase was very high and even higher than that of control, i.e. in the absence of organic solvents. For instance, in the presence of 70% (V/V) of methanol, DMF and glycerol enzymatic activity was 3.5, 1.4 and 1.2 times higher than that of 0% of organic solvents. On the contrary to most enzymes whose activity diminishes in organic solvents, the present study clearly indicated that elastase activity increases even in the presence of organic solvents. This finding means that Pseudomonas aeruginosa elastase is not only an organic solvent enzyme, but more ideal catalyst within aqueous-organic than absolutely aqueous medium.