370 M. Ugliano and P.A. Henschke
Hanseniaspora guilliermondiican produce more ethanol thanHanseniaspora
uvarumand has a better balance of volatile and non-volatile compounds, including
production of 2-phenylethyl acetate, which elicits a fruity, honey, rose-like aroma
(Table 8D.6) (Rojas et al. 2003; Swiegers et al. 2005). Cofermentation withSaccha-
romyces cerevisiaehas potential for aroma enhancement of wine.
Dekkeraspecies participate in the production of Belgium, acidic, lambic beers;
however, this species, especiallyDekkera bruxellensis, which is highly adapted to
growth in wine, is generally considered to be a spoilage yeast although some con-
sider that it adds favour complexity. These yeast produce volatile phenols, especially
ethyl phenol, ethyl guaiacol and ethyl catechol, by thereductive decarboxylation of
the grape hydroxycinnamic acidsp-coumaric, ferulic and caffeic acids, respectively.
In combination with volatile fatty acids, such as isovaleric acid, a variety of aromas
are produced in wine, including medicinal, Bandaid©R, barnyard, leathery, horsey,
smoky and spicy. The nitrogen-heterocycles, 2-acetyltetrathydropyridine and 2-
acetyl-1-pyrroline, which give the so-called ‘mousy’ off-flavour, a persistent and
very disagreeable taste, can also be produced. Strain variability in volatile phenol
production is observed such that those producing smokey or spicy aromas could be
used to add complexity but the control of this species in wineries remains a major
problem globally (Chatonnet et al. 1992b; Fugelsang and Zoecklein 2003; Grbin
and Henschke 2000; Su ́arez et al. 2007).
Schizosaccharomyces malidevoranshas been proposed for the biodeacidification
of grape must since it strongly degradesL-malic acid to a greater extent than by
closely relatedSchizosaccharomyces pombestrains. Anaerobically, malic acid is
degraded to ethanol and CO 2 , thereby giving a strong reduction in acidity. This
yeast produces H 2 S, limiting its use in winemaking. However, a mutant strain,
which utilises malic acid at a greater rate and sugar to a limited extent, has been
successfully used in red and white wine cofermentation trials withSaccharomyces
cerevisiae(Rankine 1966; Thornton and Rodriguez 1996).
Several other non-Saccharomycesyeasts, includingPichia anomala (synonyms
Candida pelliculosa, Hansenula anomala, Candida beverwijkiae), Pichia fermen-
tans (anamorphCandida lambica), Pichia membranifaciens(anamorphCandida
valida),Issatchenkia terricola,Pichia subpelliculosa (synonymHansenula subpel-
liculosa)andWilliopsis staurnus (synonymHansenula saturnus) have been par-
tially evaluated for aroma enhancement of wines (Table 8D.6) (Clemente-Jimenez
et al. 2004; Jemec and Raspor 2005; Jolly et al. 2006; Rojas et al. 2003). Yeasts
Pichia anomalaandIssatchenkia terricolahave high acetate ester production but
in cofermentation withSaccharomyces cerevisiaemore balanced wines can be pro-
duced. The high production of fruity-like ethyl esters of medium chain fatty acids,
such as the ethyl octanoate, and the rose-like aromatic alcohol 2-phenyl ethanol
byPichia fermentansare potentially useful for aroma enhancement in cofermenta-
tions. Several weakly fermentative yeastsPichia anomala, Pichia membranifaciens,
Pichia subpelliculosaandWilliopsis staurnushave also been evaluated for produc-
tion of low alcohol wines, which underaerobic conditions increases biomass and
increases ester production (Erten and Campbell 2001).