Original scientific paper

Catalytic Properties of Lipase Extracts from Aspergillus niger

Licia M. Pera ; PROIMI, Av. Belgrano y Pasaje Caseros, 4000 Tucumán, Argentina
Cintia M. Romero ; PROIMI, Av. Belgrano y Pasaje Caseros, 4000 Tucumán, Argentina
Mario D. Baigori ; PROIMI, Av. Belgrano y Pasaje Caseros, 4000 Tucumán, Argentina
Guillermo R. Castro ; Department of Biomedical Engineering, Tufts University, Medford, MA 02155, USA

Abstract

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 %.

Keywords

Aspergillus niger; substrate specificity; solvent tolerance; thermoresistance; enzyme stability; lipase screening

Hrčak ID:

109862

URI

https://hrcak.srce.hr/109862

Publication date:

15.6.2006.

Article data in other languages: croatian

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