Catalytic Properties of Lipase Extracts from Aspergillus niger

• Main Authors: Cintia M. Romero, Mario D. Baigori, Guillermo R. Castro, Licia M. Pera
• Format: Article
• Language: English
• Published: University of Zagreb 2006-01-01
• Series: Food Technology and Biotechnology
• Subjects: Aspergillus niger; substrate specificity; solvent tolerance; thermoresistance; enzyme stability; lipase screening
• Online Access: http://hrcak.srce.hr/file/161925
• ISSN: 1330-9862; 1334-2606

Screening of lipolytic strains using Rhodamine-B/olive oil plate technique allowed the selection of Aspergillus niger MYA 135. Lipase production in submerged culture containing 2 % olive oil was enhanced by more than 50 % compared to basal cultural conditions. Optimal catalytic conditions for olive oil-induced lipase were pH=6.5 and 30–35 °C. These values were shifted to the acid region (4.0–6.5) and 35–37 °C when lipase extract was produced under basal conditions. Slight changes of the residual lipase activity against the pH were found. However, preincubation at either 37 or 40 °C caused an increase in the olive oil-inducible lipolytic activity. On the contrary, lipase residual activity decreases in the 30–55 °C range when it was produced in basal medium. Lipolytic extracts were almost not deactivated in presence of 50 % water-miscible organic solvents. However, water-immiscible aliphatic solvents reduced the lipase activity between 20 and 80 %.