Secreted proteome of the psychrotolerant yeast Guehomyces pullulans in different carbon sources

ANDREA TROCHINE; NICOLAS BELLORA; VIRGINIA DE GARCIA; ROSARIO DURAN; CARLOS ROBELLO

Mar del Plata

Congreso; 51 Reunión Anual de la Sociedad Argentina de Bioquímica y Biología Molecular; 2015

Sociedad Argentina de Bioquímica y Biología Molecular (SAIB)

Our research main focus is the biotechnological potential of yeasts isolated from Patagonia extreme environments. Inthis work we have studied the secreted proteins of the psychrotolerant basidiomycetous yeast Güehomyces pullulans. First, the genome of G. pullulans strain CRUB1754 was sequenced with a Miseq, resulting in a mean coverage of 10 and a genome size of 22.6 Mb. An ab initio search for coding sequences predicted about 7000 putative CDS, which allowed building a protein database to interrogate with mass spectrometry data. For the secretome characterization, yeasts were grown on media containing glucose, starch or cellobiose as main carbon sources. Proteins from culture supernatants were concentrated by ultrafiltration. A proteomics LC-MS shotgun strategy was used to study 3 biological replicates of each condition. A total of 85 proteins were identified in all samples, from these 47 were present in at least two replicates. Proteins with the highest detection rates included alcohol oxidase, glycosidehydrolases, alpha amylase and a xylanase, the last one was the most represented protein in all conditions. An aspartic protease was exclusively identified in the presence of starch whereas the alpha amylase was highly induced. As a conclusion, a number of proteins with biotechnological potential were found and their enzymatic capabilities will be subject to future analysis.