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

Aims: The purpose of this study was to characterize the α-l-rhamnosidase of Pichia guilliermondii NPCC1053 indigenous wine strain from North-Patagonian region.Methods and Results: The optimization of yeast culture conditions was carried out and the effects of oenological parameters on α-l-rhamnosidase activity were evaluated. Additionally, the effect of direct contact with must and wine on α-l-rhamnosidase activity was assayed. This strain showed an intracellular inducible α-l-rhamnosidase activity. This enzyme was active at pH, glucose and SO concentrations usually found at the beginning of the fermentation as well as retained high levels of activity after 24 h of incubation in must. Furthermore, P. guilliermondiiα-l-rhamnosidase was able to release monoterpenols and alcohols from grape glycosidic extracts.Conclusions: The α-l-rhamnosidase belonging to P. guilliermondii indigenous wine yeast strain showed mainly an intracellular location and evidenced interesting oenological characteristics.Significance and Impact of the Study: This study contributes to the knowledge of α-l-rhamnosidases from yeast origin because at present, there are few reports about this enzymatic activity in these micro-organisms. In addition, this work is relevant to the regional wine industry considering that this enzyme could be used in the production of more aromatic young wines. © 2010 The Authors. Journal of Applied Microbiology © 2010 The Society for Applied Microbiology.