LIPASE FROM A BRAZILIAN STRAIN OF PENICILLIUM-CITRINUM

A lipases (glycerol ester hydrolases E. C. 3.1.1.3) from a brazilian s train of Penicillium citrinum has been investigated. When the microorg anism was cultured in the simple medium (1.0% olive oil and 0.5% yeast extract), using olive oil in as carbon source in the inocula, the enz yme extracted showed maximum activity (409 IU/mL). In addition, decrea se of yeast extract concentration also reduces the lipase activity. Ne vertheless, when yeast extract was replaced by ammonium sulfate, no ac tivity was detected. Purification by precipitation with ammonium sulfa te showed best activity in the 40-60% fraction. The optimum temperatur e for enzyme activity was found in the range of 34-37 degrees C. Howev er, after 30 min at 60 degrees C, the enzyme was completely inactivate d. The enzyme showed optimum at pH 8.0. The dried concentrated fractio n (after dialysis and lyophilization) maintained its lipase activity a t room temperature (28 degrees C) for 8 mo. This result in lipase stab ility suggests an application of lipases from P. citrinum in detergent s and other products that require a high stability at room temperature .