Femi-Ola T. O.^1,, Odeyemi A. T.¹, Olaiya B. S.¹, Ojo O. O.¹

An extracellular lipase from Bacillus subtilis isolated from oil polluted soil was partially purified and characterized in this study. The enzyme was purified to 19.36 fold and the molecular weight was estimated. The effect of temperature, time, metal ion and pH was also determined. The molecular weight of the enzyme was estimated to be 48.63 kDa by SDS-PAGE. The optimum temperature was 60¡ãC, while the enzyme exhibited appreciable thermostability retaining 70% of activity at 70¡ãC for 1h. The lipase was most active in the pH range of 7-9 with an optimum activity at pH 8.0. The enzyme activity declined in the presence of Al³⁺ and Fe²⁺, while Na⁺ stimulated the activity. Olive oil was found to be the preferred substrate. The maximum velocity V_max and K_m of the lipase during the hydrolysis of olive oil were 39.45 ¦Ìmol/min/ml and 20.01 mM respectively.

Lipase, olive oil, Bacillus subtilis, thermostability