Purification and Characterization of a Thermostable Lipase from Geobacillusthermodenitrificans IBRL-nra

Abstract

◦C in cultivation mediumcontaining;glucose1.0%(w/v);yeastextract1.25%(w/v);NaCl0.45%(w/v)oliveoil0.1%(v/v)withagitationof200rpm for 24 hours. The extracted extracellular crude thermostable lipase was purified to homogeneity by using ultrafiltration, Heparinaffinity chromatography, and Sephadex G-100 gel-filtration chromatography by 34 times with a final yield of 9%. The molecular weight of the purified enzyme was estimated to be 30kDa after SDS-PAGE analysis. The optimal temperature for thermostable lipase was 65 ◦ C and it retained its initial activity for 3 hours. Thermostable lipase activity was highest at pH 7.0 and stable for 16 hours at this pH at 65 ◦ C. Thermostable lipase showed elevated activity when pretreated with BaCl2 ,C aCl2, and KCl with 112%, 108%, and 106%, respectively. Lipase hydrolyzed tripalmitin (C16) and olive oil with optimal activity (100%) compared to other substrates.