CONICET | Buscador de Institutos y Recursos Humanos

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 enhace the wine aromatic profiles is a prerequisite. For this reason cold active pectinases are requiered. 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 (rotavap, 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.