High Potential of Pichia kluyveri and Other Pichia Species in Wine Technology

Abstract

The surfaces of grapes are covered by different yeast species that are important in the first stages of the fermentation process. In recent years, non-Saccharomyces yeasts such as Torulaspora delbrueckii, Lachancea thermotolerans, Metschnikowia pulcherrima, and Pichia kluyveri have become popular with regard to winemaking and improved wine quality. For that reason, several manufacturers started to offer commercially available strains of these non-Saccharomyces species. P. kluyveri stands out, mainly due to its contribution to wine aroma, glycerol, ethanol yield, and killer factor. The metabolism of the yeast allows it to increase volatile molecules such as esters and varietal thiols (aroma-active compounds), which increase the quality of specific varietal wines or neutral ones. It is considered a low- or non-fermentative yeast, so subsequent inoculation of a more fermentative yeast such as Saccharomyces cerevisiae is indispensable to achieve a proper fermented alcohol. The impact of P. kluyveri is not limited to the grape wine industry; it has also been successfully employed in beer, cider, durian, and tequila fermentation, among others, acting as a promising tool in those fermentation processes. Although no Pichia species other than P. kluyveri is available in the regular market, several recent scientific studies show interesting improvements in some wine quality parameters such as aroma, polysaccharides, acid management, and color stability. This could motivate yeast manufacturers to develop products based on those species in the near future.

Commercially Available Non-Saccharomyces Yeasts for Winemaking: Current Market, Advantages over Saccharomyces, Biocompatibility, and Safety

“…The following commercial strains of Pichia kluyveri are offered: Viniflora FrootZen (monoculture offered by CHR Hansen, Hørsholm, Denmark) and Trillyeast (in consortium with Kazachastania servazzii, offered by BioEnologia, Oderzo, Italy) (Table 1). Recently, the commercial strain Pichia kluyveri WLP605 (Vintner's Harvest, Yakima, WA, United States) was reported and recommended to confer floral and rose petal aromas [28].…”

“…However, the concentration of this acid was not high enough to be detected in the sensory analysis. It was suggested that the synthesis of isovaleric acid can be considered a criterion for the selection of P. kluyveri [28] and that its esterification can produce the ethyl ester of 3-methyl-butanoic acid, which has a pleasant fruity aroma.…”

Effects of Simultaneous Co-Fermentation of Five Indigenous Non-Saccharomyces Strains with S. cerevisiae on Vidal Icewine Aroma Quality

“…Using Starmerella bacillaris mixed with S. cerevisiae produced significantly lower levels of acetic acid, ethanol, and ethyl acetate, and higher amounts of glycerol, higher alcohols, and esters [ 13 ]. P. kluyveri improves wine quality parameters such as thiol, fruity ester, and terpene concentrations, mainly in sequential fermentation [ 14 ]. Higher concentration of medium-chain fatty acids was associated with the higher biomass suppression of H. uvarum in co-inoculation with killer S. cerevisiae , which resulted in the increased formation of fruity esters, but effectively restricted the production of ethyl acetate [ 15 ].…”

The potential of spent coffee grounds hydrolysates fermented with Torulaspora delbrueckii and Pichia kluyveri for developing an alcoholic beverage: The yeasts growth and chemical compounds modulation by yeast extracts

“…Pichia kluyveri , another popular non- Saccharomyces yeast, is well known for its characteristics of low ethanol production but high acetate esters (e.g. 2-phenylethyl acetate) production ( Vicente et al, 2021 ). Previous studies have demonstrated that P. kluyveri improved the aroma quality of various types of alcoholic beverages including fruits media (e.g.…”