Production of extracellular lipase by the phytopathogenic fungus "Fusarium solani" FS1

RESUMO

A Brazilian strain of "Fusarium solani" was tested for extracellular lipase production in peptone-olive oil medium. The fungus produced 10,500 U.L(E-1) of lipase after 72 hours of cultivation at 25ºC in shake-flask at 120rpm in a medium containing 3(per cent) (w/v) peptone plus 0.5(per cent)(v/v) olive oil. Glucose (1(per cent) w/v) was found to inhibit the inductive effect of olive oil. Peptone concentrations below 3(per cent)(w/v) resulted in a reduced lipase production while increased olive oil concentration (above o.5(per cent)) did not further stimulate lipase production. The optimum lipase activity was achieved at pH 8.6 and 30ºC and a good enzyme stability (80(per cent) activity retention) was observed at pH ranging from 7.6 to 8.6, and the activity rapidly dropped at temperatures above 50ºC. Lipase activity was stimulated by addition of n-hexane to the culture medium supernatatnts, in contrast to incubation with water-soluble solvents