The use of detergent-based aqueous two-phase systems for the isolation of extracellular proteins: purification of a lipase from Pseudomonas cepacia.

The partitioning of a variety of extracellular lipases, both pro- and eucaryotic, in detergent-based aqueous two-phase systems was examined. The results revealed that all procaryotic lipases showed a clear preference for the detergent-rich coacervate phase. In contrast, all eucaryotic lipases were significantly excluded from this phase, most probably caused by their glycosylation. The potential of such detergent-based systems for the isolation of extracellular lipases directly from cell-free culture broth was analyzed using the bacterium Pseudomonas cepacia (DSM 50181). This strain was identified after a limited screening for lipase activity. About 76% of the lipase could be extracted into the coacervate phase in just one purification step, leading to a four-fold concentration of lipase and a purification factor of 24.