CINDEFI   05381
CENTRO DE INVESTIGACION Y DESARROLLO EN FERMENTACIONES INDUSTRIALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Thermostability of free and immobilized Aspergillus niger chlorogenate hydrolase
Autor/es:
BUTIUK, A.; ADACHI, O.; MIGNONE, C.; HOURS, R.
Lugar:
Mar del Plata
Reunión:
Encuentro; VIII Encuentro Latinoamericano y del Caribe de Biotecnología; 2013
Institución organizadora:
REDBIO Argentina
Resumen:
Chlorogenate hydrolase (EC 3.1.1.42, CHase) was formed by Aspergillus niger AKU 3302 grown in
Czapek medium containing 0.125% (w/v) of concentrated yerba mate extract as
inducer. The cell-free extract was prepared by grinding mycelia in a mortar in
the presence of Na-phosphate buffer and centrifuging the resultant suspension.
Free CHase solution and CHase-immobilized (mycelia CHase) were put in tubes
dipped in a water bath and kept at different combinations of time (20-60 min)
and temperature (45-60°C) according to a Doehlert experimental design. The
residual CHase activity was measured and expressed as % relative to a control
(without heat treatment). Thermostability of free and immobilized CHase activity
was compared. Immobilized CHase remained stable up to 55°C and 60 min retaining
about 90% CHase activity whereas free CHase only retained about 40% of
its initial activity under the same conditions. At temperatures
higher than 55°C, the activity of the free enzyme declined rapidly. Immobilized
CHase was more stable than the free enzyme and at 65°C and 60 min still
retained 50% of residual activity. Once immobilized-CHase was heated at 55°C for 60 min,
vegetative mycelial growth was negative thus allowing to be packed in a column
as stable immobilized catalyst.