Characterization of α-rhamnosidase activity from a Patagonian Pichia guilliermondii wine strain

Abstract

Aims: The purpose of this study was to characterize the a-l-rhamnosidase ofPichia guilliermondii NPCC1053 indigenous wine strain from North-Patagonianregion.Methods and Results: The optimization of yeast culture conditions was carriedout and the effects of oenological parameters on a-l-rhamnosidase activitywere evaluated. Additionally, the effect of direct contact with must and wineon a-l-rhamnosidase activity was assayed. This strain showed an intracellularinducible a-l-rhamnosidase activity. This enzyme was active at pH, glucoseand SO2 concentrations usually found at the beginning of the fermentation aswell as retained high levels of activity after 24 h of incubation in must. Furthermore,P. guilliermondii a-l-rhamnosidase was able to release monoterpenols and alcohols from grape glycosidic extracts. Conclusions: The a-l-rhamnosidase belonging to P. guilliermondii indigenouswine yeast strain showed mainly an intracellular location and evidenced interestingoenological characteristics.Significance and Impact of the Study: This study contributes to the knowledgeof a-l-rhamnosidases from yeast origin because at present, there are fewreports about this enzymatic activity in these micro-organisms. In addition,this work is relevant to the regional wine industry considering that this enzymecould be used in the production of more aromatic young wines.