INVESTIGADORES
MORATA vilma ines
congresos y reuniones científicas
Título:
Characterization of a microbial pectinolytic preparation active at low temperatures for vinification
Autor/es:
CABEZA, M.S.; OSORIO N.E.; MARGARA D.D.; MORATA DE AMBROSINI V.I.; CASTRO G.R.
Lugar:
Trivandrum, India.
Reunión:
Conferencia; Internacional Conference on New Horizons in Biotechnology (NHBT 2007); 2007
Resumen:
Cold adapted enzymes are often characterised by increased catalytic efficiency and a greater structural flexibility that allow catalyzing reactions at low temperature. In winemaking is important working at low temperatures to enhace the wine aromatic profiles. For this reason cold active pectinases are requiered. Psychrotolerant microorganisms were isolated and selected according to production of pectinolytic enzymes with satisfactory activity at low temperatures (10-15ºC). In previous studies, grapes from the enological D.O. (guarantee of origin and quality) region San Rafael (Mendoza, Argentina) were employed for the isolation, corresponding to different varieties and mature states. The strain with greatest activity, Bacillus SC-H, was selected. In this work, this Bacillus was classified using the API system (BioMerieux). Its enzymatic preparation was characterized through protein electrophoresis, using zymograms in order to identify the lytic action of the proteinaceous components. As well, hydrolysis reaction products were analyzed using TLC. The sugar fermentative profile allowed classifying the microorganism as Bacillus subtilis, although with a low discrimination level, which suggest applying genetic techniques to analyze its affiliation. Two bands belonging to the protein electrophoresis of the concentrate enzymatic preparation (rotavapor, 10x) were recognized, using zymographic studies, as hydrolases and esterases. The TLC analysis showed the presence of monogalacturonic acid and intermediate products between this one and polygalacturonic acid, probably compatible with the presence of di and trigalacturonates which showed an endo lytic action, more favorable for effective juice and substances extraction.