Purification and characterization of an extracellular lipase from Clostridium tetanomorphum

The strictly anaerobic bacterium Clostridium tetanomorphum formed an extracellular lipase when the growth medium contained glycerol in addition to fermentable substrates such as L-glutamate or glucose. The lipase was purified from the concentrated culture supernatant and exhibited a final specific activity of 900 U/mg. The purified lipase had a Stokes' radius of 5.0 nm and a sedimentation coefficient of 5.7S. The native molecular mass calculated from these values was 118,000 Da, which is considerably higher than the molecular mass calculated by PAGE (70,000 Da). With p-nitrophenyl esters of different fatty acids as substrates enzyme activity was highest when the acyl chain was short (C-2). The purified lipase showed no protease or thioesterase activity.