Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
18663 | Enzyme and Microbial Technology | 2006 | 9 Pages |
Extracellular lipases were obtained from solid (SSF) and submerged (SmF) thermotolerant Rhizopus homothallicus fungus cell cultures and purified to homogeneity. The two enzymes are monomers having a molecular mass of 29.5 kDa and an identical protein structure, since the N-terminal sequences and peptide maps were identical. However, some of their properties are different, namely the specific activity on trioctanoin (8600 U/mg with SmF and 10,700 U/mg with SSF), the temperature at which maximum activity occurs (30 °C with SmF and 40 °C with SSF) and the thermal stability (half-lives at 50 °C of 0.44 h with SmF and 0.72 h with SSF). These differences between the kinetic properties suggest that when they were tested, one or both fungal lipases might still have been associated with non-proteic compounds originating from the culture medium.