Hanseniaspora uvarum

The yeasts also have been evaluated for antifungal activity. Spadaro and others (2008) reported that Hanseniaspora uvarum, Rhodotorula spp., and Metschnikowia pulcherrima reduced the development of P. expansum on apples. In this work the biocontrol effectiveness was assessed on four apple cultivars, Golden Delicious, Stark Delicious, Granny Smith, and Royal Gala. The efficacy was higher on the cv. Golden Delicious. 

Genes for pyruvate decarboxylases have been isolated from yeasts and fungi such as Saccharomyces cerevisiae [86-90], Hanseniaspora uvarum [91], Klyveromyces marxianus [92], Klyveromyces lactis [93], Neurospora crassa [94], Aspergillus parasiticus [95], plants, like maize (Zea maize) [96,97], rice (Oryza sativa) [98], tomato (Lycopersicon esculentum) [99,100], pea (Pisum sativum) [101], and tobacco (Nicotiana tabacum) [102] and from the bacterium Zymomonas mobilis [103-106]. 

Indeed, grapes are a primary source of microorganism, and many studies have shown that natural fermentation starts with those species predominant on grapes at harvest time (Fleet et ah, 2002). These can include the apiculate yeasts (Hanseniaspora uvarum and Kloeckera apicu-lata), Metschnikozvia, Candida, Pichia, Khodotorula, and Kluyveromyces. In contrast, although it is the main wine fermentation yeast, Saccharomyces have only rarely been isolated from vineyards (Martini, 1993 Martini et ah, 1996 Pretorius, 2000 Sabate et ah, 1998), since it is closely associated with the winery environment (Ciani et ah, 2004). 

Metschnikowia pulcherrima (Candida pulcherrima) Hanseniaspora uvarum (Kloeckera apiculata)... 

Hanseniaspora uvarum (anamorph Kloeckera apiculata) is commonly the major yeast present on the grape berry and in musts and juices, but due to low tolerance to ethanol, populations decline quickly in the presence of Saccharomyces cerevisiae. Strains are typically characterised by low fermentative ability and high production of acetic acid, ethyl acetate and acetaldehyde, which render such strains more suitable to vinegar production. Nevertheless, Ciani and Maccarelli (1998) surveyed 37 isolates and found considerable variability, with some strains producing concentrations of these compounds approaching concentrations present in wines made with Saccharomyces cerevisiae (Table 8D.6). Cofermentation fermentation with Saccharomyces cerevisiae can produce wines with an acceptable balance of volatile and non-volatile compounds and sensory scores (Ciani et al. 2006 Jemec and Raspor 2005 Jolly et al. 2003b Zohre and Erten 2002). 

Hanseniaspora guilliermondii can produce more ethanol than Hanseniaspora uvarum and 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 with Saccha-romyces cerevisiae has potential for aroma enhancement of wine. 

Abd-El-Al and Phaff (39) also found -glucanase activities in intracellular extracts of Hanseniaspora valbyensis and Hanseniaspora uvarum and in the culture fluid of H. valbyensis. In contrast to the other yeasts, pustulan was not hydrolyzed by these preparations, and laminarin was hydrolyzed yielding oligosaccharides. This suggested that these yeasts produced an endo-/3- (1 — 3) -glucanase, and subsequently such an enzyme was partially purified from the culture fluid of H. valbyensis (39). 

It is generally accepted that in the case of sound fruit, population density and diversity of native (formerly referred to as wild ) yeasts is limited, ranging from less than 10 to 10 CFU/berry. The most frequently isolated native species are the so-called apiculate yeasts, Kloeckera apiculata, and its sexual counterpart, Hanseniaspora uvarum. These lemon-shaped small yeasts get their name from repeated budding at both poles (see Fig. 3-1) and often account for over 50% of the total yeast flora recovered from fruit. 

Radler, F., P. Pfeiffer, and M. Dennert. 1985. Killer toxins in new isolates of the yeast Hanseniaspora uvarum and Pichia kluyveri. FEMS Microbiol. Lett. 29 269-271. 

Sponholz, W.R., H.H. Dittrich, and K. Han. 1990. Die Beeinflussung der Garung und der Essigsaureethylester-bildund durch Hanseniaspora uvarum. Vitic. Enol. Sci. 45 65-72. 

To distinguish yeasts that can produce ascospores from those that do not, mycologists use a dual taxonomy for classification. Unfortunately, the nomenclature for anamorph/teleomorph combinations is frequently different. Examples of sexual/asexual or teleomorph/anamorph yeasts include Dekkera/Brettanomyces, Metschnikowia pulcherrima/Candida ptdcher-rima, Hanseniaspora uvarum/Kloeckera apiculata, and Torulaspora delbrueckii/ Candida colliculosa. Some yeasts only exist in the anamorphic form because sporulation has yet to be demonstrated (e.g., Candida vini). 

Fig. 1.19. Observation of two enological yeast species having an apiculated form, (a) Hanseniaspora uvarum. (b) Saccharomycodes ludwigii...

Candida stellata Candida vini Candida famata Dekkera anomala Dekkera bruxellensis Hanseniaspora uvarum Metschnikowia pulcherrima Pichia anomala Pichia fermentans Pichia membranefaciens Saccharomyces cerevisiae Saccharomycodes ludwigii Kluyveromyces thermolerens Schizosaccharomyces pombe Zygosaccharomyces bailii... 

Species other than Saccharomyces, in particular apiculated yeasts (Hanseniaspora uvarum, Kloeckera apiculata), are present on the grape and are sometimes found at the beginning of fermentations. These species have fewer polymorphous karyotypes and fewer bands than in Saccharomyces. Versavaud et al. (1993) differentiated between strains of apiculated yeast species and Candida famata by using restriction endonucleases at rare sites (Not 1 and Sfl I). The endonucleases cut the chromosomes into a limited number of fragments, which were then separated by pulse-field electrophoresis. 

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