Selection and Characterization of Cold-Active Alpha-L-Rhamnosidase Producer Strains with Application in Wine Industry

ALVARENGA A.E.; AREVALO M.I.; ABATE C.M

Cordoba. Argentina

Congreso; VI Congreso Argentino de Microbiologia General. SAMIGE; 2009

Sociedad Argentina de Microbiologia General (SAMIGE)

  Alpha-L-rhamnosidases catalyze hydrolysis of rhamnoside substrates, releasing L-rhamnose. Several technological applications of these enzymes in industrial rhamnoside hydrolysis have been reported, including removal of bitterness from citrus juices. In addition, alpha-L-rhamnosidases are used in the release of flavour compounds from terpenyl glycosides for the enhancement of aroma in grape juices and derived beverages. The aims of this work were selection and taxonomical characterization of marine microorganisms isolated from Beagle Channel. Enzymatic activity was determined at 25 °C and 5 and 7 pH values. 58 isolates were cultivated in Brunner Minimal Medium (MMB) with rhamnose or naringine. 21 strains were selected at 8 and 20 °C, and 5 and 7 pH values. The selected isolates were separated into groups according to ARDRA profiles. 16S rDNA amplifications were sequenced and the phylogenetics trees were constructed. The gene sequences allowed us to determine their association with the genera Serratia, Shewanella, Pseudomonas, Halomonas and Aeromonas, members of the Proteobacteria class. Enzymatic activity was determined using 4-Nitrophenyl alpha-L-rhamnopyranoside. Selected strains present promissory qualities related to alpha-L-rhamnosidase expression at low pH values and temperatures.