Purification and characterization of an alkaline lipase from Pseudomonas fluorescens AK102

An extracellular, novel alkaline lipase produced by Pseudomonas fluorescens AK102 was purified by ultrafiltration, ammonium sulfate precipitation, and DEAE-Toyopearl 650M and Phenyl-Toyopearl 650M column chromatographies. The purified enzyme was homogeneous on SDS-PAGE. The molecular weight was estimated to be about 33,000 by SDS-PAGE. The isoelectric point was pH 4.0 by isoelectric focusing. The pH stability was 4 to 10 and the optimum pH was 8 to 10. The optimum temperature was 55 degrees C and the enzyme was stable below 50 degrees C. The enzyme unspecifically liberated short chain to long chain fatty acids from p-nitrophenyl esters, methyl esters, and triglycerides. In the presence of an anionic surfactant, the enzyme was characteristically stable. These results suggested that the enzyme can be used as a home laundry product ingredient.