Partial characterization of esterase and lipase from Aspergillus niger MYA 135

ROMERO, C; PERA, L; BAIGORÍ, M

Tafi del Valle. Tucuman

Jornada; XXIII Jornadas Científicas Asociación de Biología de Tucumán. Tafi del Valle Tucumán; 2006

Asociaciòn de Biologìa de Tucumàn

PARTIAL CHARACTERIZATION OF ESTERASES AND LIPASES FROM A. NIGER MYA 135 Romero C, Pera L, Baigorí M. PROIMI-CONICET Belgrano y Caseros, 4000 Tucumán. Tel: 4344888. E-mail: baigori@proimi.org.ar Introduction: Esterases (EC 3.1.1.1) and lipases (EC 3.1.1.3) catalyze hydrolysis and synthesis of esters. Their applications include hydrolysis of fats and oils, resolution of racemic mixtures, etc. Objective: The aim of this work was to study the effects of different conditions on the stability of esterases and lipases from Aspergillus niger MYA 135. Materials and methods: Culture supernatant was preincubated at several pH values and temperatures. Residual activities were analyzed by nPAGE using either á-naphtyl acetate or á-naphtyl mirystate as substrates. Activities already separated by nPAGE were also used to evaluate their stabilities in organic solvents. Results and conclusions: Enzymes were active within the pH and the temperature range tested. Except at pH 9 and at 55°C where some bands were not detected. Enzymes preincubated in either 2-propanol, 2,3-butanodiol or acetone showing the same pattern that the control without incubation. Some bands were not detected after preincubation with propanol, n-hexane, hexanol or n-heptane. No band was observed after preincubation with butanol. One of the bands shows a good stability pattern which justifies its application in biocatalysis. This work was supported by grants PIP 6203 and PICTO 761.