Production, purification and characterization of an extracellular lipase from the yeast, Cryptococcus sp S-2

A number of factors affecting the production of extracellular lipase by Cry ptococcus sp. S-2 were investigated. Consecutive optimization of nitrogen, carbon sources and inducers enhanced lipase activity and under optimum cond itions the lipase activity was 65.7 U/ml of the culture medium in 120 h at 25 degreesC and at pH 5.6. Sardine oil, soy bean oil and triolein were effe ctive inducers for lipase production. The lipase was purified 17.1-fold to homogeneity by ultrafiltration and SP-5PW cation exchange chromatography. I ts molecular mass was 22 kDa on SDS-PAGE. The enzyme showed maximum activit y at pH 7.0 and at 37 degreesC and was stable between pH 5.0 and 9.0 and at temperatures up to 50 degreesC. The addition of DMSO and diethyl ether to the assay mixture in the range of 0-10% (v/v) stimulated the enzyme signifi cantly, while benzene had an inhibitory effect. The enzyme was also stable in different organic solvents at a concentration of 50% (v/v) for 60 min. T he substrate specificity towards simple triglycerides and oils was broad an d the enzyme was regarded as a partial glyceride hydrolase. The enzyme has good potential for the hydrolysis of vegetable oils, which are industrially and economically important for the production of biodiesel. (C) 2000 Elsev ier Science Ltd. All rights reserved.