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

TROCHINE A., BELLORA N., DE GARCIA V., DURÁN R., BATTHYANY C., ROBELLO C.

Mar del Plata

Congreso; SAIB; 2015

Our research main focus is the biotechnological potential of yeasts isolated from Patagonia extreme environments. In this 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 6000 putative CDS, which allowed building a protein database to interrogate with mass spectrometry data. For the secretome characterization, yeasts were grown on media containing 1% of 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. A number of predicted proteins presented signal peptides, these could be intracellular proteins. Proteins with the highest detection rates included alcohol oxidase, glycoside hydrolases, alpha amylase and a xylanase, the last one was the most represented protein in all conditions. The alpha amylase was highly induced in the presence of starch. As a conclusion, a number of proteins with biotechnological potential were found and their enzymatic capabilities will be subject to future analysis.