Challenges of the Non-Conventional Yeast Wickerhamomyces anomalus in Winemaking

Beatriz Padilla,Paloma Manzanares,Jose Gil

doi:10.3390/fermentation4030068

Abstract

Nowadays it is widely accepted that non-Saccharomyces yeasts, which prevail during the early stages of alcoholic fermentation, contribute significantly to the character and quality of the final wine. Among these yeasts, Wickerhamomyces anomalus (formerly Pichia anomala, Hansenula anomala, Candida pelliculosa) has gained considerable importance for the wine industry since it exhibits interesting and potentially exploitable physiological and metabolic characteristics, although its growth along fermentation can still be seen as an uncontrollable risk. This species is widespread in nature and has been isolated from different environments including grapes and wines. Its use together with Saccharomyces cerevisiae in mixed culture fermentations has been proposed to increase wine particular characteristics. Here, we review the ability of W. anomalus to produce enzymes and metabolites of oenological relevance and we discuss its potential as a biocontrol agent in winemaking. Finally, biotechnological applications of W. anomalus beyond wine fermentation are briefly described.

Highlights

Saccharomyces cerevisiae is the main microorganism involved in the alcoholic fermentation of grape must
The use of selected S. cerevisiae strains has provided an improvement in the control and homogeneity of fermentations
Beyond the contribution of non-Saccharomyces yeasts to wine aroma complexity [3], these yeasts can help address some of the modern challenges in winemaking, including the reduction of the ethanol content of wine [4,5,6,7] or the control of wine spoilage [8,9]

Summary

Introduction

Saccharomyces cerevisiae is the main microorganism involved in the alcoholic fermentation of grape must. Yeast isolations from Malvar grape musts pointed out W. anomalus as one of the most frequent non-Saccharomyces species, and in addition, the yeast was a good producer of extracellular enzymes which may be beneficial in winemaking [29]. Strains identified as W. anomalus or its former names have been reported to produce glycosidases such as β-D-glucosidase, α-L-arabinofuranosidase, α-L-rhamnosidase, and β-D-xylosidase, which are involved in the release of aroma compounds from grape precursors [3]. A study conducted on 20 different yeast species showed that all tested strains of H. anomala presented β-glucosidase activity [46]. Besides showing β-D-glucosidase activity, other P. anomala/W. anomalus strains exhibited α-L-arabinofuranosidase or β-D-xylosidase activity in screenings as well, including more than 300 and 100 wine yeast isolates, respectively [49,50]. Characteristics and its ethanol and polysaccharides production [61]

Production

Findings

Final Considerations