Purification and characterization of an organic solvent-stable lipase from Pseudomonas stutzeri LC2-8 and its application for efficient resolution of (R, S)-1-phenylethanol

An organic solvent-stable lipase from newly isolated solvent-tolerance bacterium Pseudomonas stutzeri LC2-8 was purified by acetone precipitation and anion exchange chromatography. The apparent molecular mass of the purified lipase was estimated by SDS-PAGE to be 32kDa. The open reading frame (ORF) of lipase LC2-8 encodes 311 amino acids with 287 amino acid residues in the mature lipase which shared 96% homology at the amino acid level with the putative lipase LipC from Pseudomonas stutzeri A1501. The optimum pH and temperature for lipase activity were 8.0 and 30°C, respectively. Its hydrolytic activity was found to be highest towards p-nitrophenyl caproate (C8). Lipase LC2-8 showed high tolerance in the presence of various organic solvents. Most of the hydrophilic solvents tested strikingly enhanced the activity and stability of lipase LC2-8. The half-life of lipase LC2-8 was extended to 10-fold in the presence of isopropanol, acetone, ethanol and methanol. The transesterification resolution of (R, S)-1-phenylethanol by lipase LC2-8 was carried out with the yield of 47.6%, the enantiomeric excess of residual substrate (ee _s) was 99.9%, giving an E-value over 200. The solvent-stable lipase LC2-8 showed an attractive potency for application in biocatalysis in non-aqueous systems.