INVESTIGADORES
CABEZA Maria Silvina
congresos y reuniones científicas
Título:
Characterization of a new 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:
NIIST, Trivandrum, India
Reunión:
Conferencia; International Conference on New Horizons in Biotechnology (NHBT 2007); 2007
Institución organizadora:
National Institute for Interdisciplinary Science & Technology (NIIST), (Formerly Regional Research Laboratory) y The Biotech Research Society (BRSI)
Resumen:
Cold adapted enzymes are often characterised by increased catalytic efficiency and a greater structural flexibility that allows catalyzing reactions at low temperature. In winemaking work at low temperatures to enhance the wine aromatic profiles is a prerequisite. For this reason cold active pectinases are required. In previous studies, grapes corresponding to different varieties and mature states from San Rafael (Mendoza, Argentina), a region with enological D.O. (guarantee of origin and quality) were selected for microbial isolation. Psychrotolerant microorganisms were isolated and selected based on the production of pectinolytic enzymes with satisfactory biocatalytic activity at low temperatures (10-15ºC). The strain with greatest activity, Bacillus sp. SC-H, was selected. The Bacillus sp. SC-H was classified using the morphological and biochemical tests using statistic tools. 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 in the Bacillus subtilis cluster, although with a low discrimination level. 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 favourable for effective juice and substances extraction.