CHARACTERIZATION OF A SOLVENT TOLERANT LIPASE FROM Aspergillus niger MYA 135

CINTIA ROMERO; FLAVIA LOTO; LICIA PERA; MARIO BAIGORI

Puerto Madryn

Congreso; XLVI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2010

Lipase catalyses the hydrolysis of triglycerides at the oil-waterinterfaces. This reaction is reversible and the enzyme also catalysesthe synthesis of esters in microaqueous conditions. Previously, wereported the presence of three enzymatic bands with lipolyticactivity from Aspergillus niger MYA 135 olive oil-inducedsupernatant. In the present work, we selected lipase 1 for itspurification and characterization, especially for its stability in thepresence of various organic solvents. This activity was purified bytwo methods, electro-elution and DEAE-Sepharose anionexchangechromatography leading for each one to 8.4-fold and 47%and 16.6-fold and 53.4% of purification and recovery, respectively.Lipase 1 showed the following main characteristics: maximumactivity at 37°C, pH 7.0; molecular mass, 68 KDa; pI 5.1; and a Kmvalue of 0.99 mM for C18 (p-NP stearate). The purified lipase wasalso digested with trypsin and analyzed by HPLC-MS/MS. Thesequences of the peptides did not show similarity with other lipases.Concerning the reactivity of this enzyme in a solvent free medium, atransesterification activity value of 0.78 ± 0.01 U/L was obtainedyielding ethyl stearate as a product. Thus, these results show avaluable solvent-tolerant lipase for biodiesel production.