# Biotechnological Approaches to Lowering the Ethanol Yield during Wine Fermentation
## 3 Alternative Wine Yeast Species
Pure culture & 1.7 & [38] \\  & 210–240 1  & standard & No 4  & at 50\% sugars & 0.8–0.9 & [39] \\ _Metschnikowia pulcherrima_ & 230–240 1  & standard & No 4  & at 50\% sugars & 0.9–1.6 & [40] \\  & 210–240 1  & standard & No 4  & at 50\% sugars & 1.0–1.1 & [39] \\  & 240 2 & standard & No 4  & & 0.1 (1/10) & 1.0 & [38] \\  & 230 1 2 2 & standard & No 4  & & 3 days & 0.8–1.25 & [41] \\  & 264 & standard & No different 4  & 3 days & 1.0 & [42] \\  & 260 1 2 & 48 h & No 4  & 48 h & 0 & 3.7 & [43] \\  & 212 1  & DO = 20\% 3 days & Negative 4  & 72 h & 3.6 & [44] \\  & 220 1 2 & 3 VVH 72 h & No 4  & 72 h & 1.5 & [45] \\  & 224 & standard & Different 24 h & 0.5–0.6 & [46] \\  & 250 & standard & No 48 h & 0.5 & [47] \\  & 212 1  & 212 1  & & 20 20  & & 20  & & 20  & 1.5–3 VVH 72 h & No 4  & 72 h & 0.6–1.3 & [49] \\  & 223 23 & standard & Positive 4  & 48 h & 0.9 & [50] \\  & 230–236 & standard & Different 4  & 230  & 30  & & 30  & 24 h & 2.5 & [51] \\  & 223 & standard & Positive 4  & 4 days & 0.5 & [52] \\  & 195 1  & 1.5–3 VVH 72 h & No 4  & 1.5–3 VVH 72 h & No 4  & 72 h & 0.9–1.0 & [45] \\  & 206 1 20 20 20 20 20 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 200 In 2011, [PERSON] and [PERSON] [63] studied the ethanol yield of several strains of _S. cerevisiae_, _S. urarum/bayanus_, _Candida zemplinina_ (currently _Starmerella bucillaris_) and _Candida stellata_. All of the other species showed a lower ethanol yield than _S. cerevisiae_, in particular C. _zemplinina_ isolates. In addition, this species is fructophilic and shows a high glycerol yield. A great number of strains of this species have been explored for ethanol production [64,65]. Wines made with the selected strains contained, at best, 0.6% ABV less than the control wine [46,47]. [PERSON] et al. (2014) [66] assessed the ethanol yield of 32 strains belonging to 8 different species, compared to a control strain of _S. cerevisiae_, and found that the species _Hansenispora uarum_ showed the lowest yield, followed by _Zygosaccharomyces sapae_ and _Zygosaccharomyces bisporus_. The authors highlight the variability among strains of the same species, and the correlation found between ethanol yield and secondary metabolite production. [PERSON] et al. (2017) [67] also selected a strain of _H. urarum_ among 117 strains belonging to 32 different species. Malbec wine produced with the selected strain [50] had a 0.9% drop in ethanol in compared to that made from _S. cerevisiae_, and a good qualification in a sensory analysis. [PERSON] et al. (2014) [40] studied the ethanol yield and sugar consumption of 50 yeast strains, with the aim of selecting suitable strains to lower the alcohol content of wine. The authors highlighted the potential of strains of the species _C. stellata_, _Schizosaccharomyces mallezvous_ and, mainly, _M. pulcherrina_. A selected strain of _M. pulcherrina_ was used for sequential fermentations with _S. cerevisiae_, and allowed for an ethanol reduction of 1.6% (_v_/_v_) for Shiraz must and 0.9% (_v_/_v_) for Chardonnay must. An increase in ethyl acetate and 2-methyl) propanol was observed, which can negatively impact the wine quality. More recently, they fermented Merlot must with _M. pulcherrina_ in a sequential inoculation with _S. cerevisiae_[38]. Compared to wine inoculated with _S. cerevisiae_, wine from spontaneous fermentation contained 0.7% (_v_/_v_) less ethanol, and wine fermented by _M. pulcherrina_ contained 1% (_v_/_v_) less. In the sensory analysis, spontaneously fermented and _M. pulcherrina_ wines were indistinguishable, and very similar to the control. Coinoculation with _M. pulcherrina_ and _S. urarum_, in sequential inoculation with _S. cerevisiae_, allowed a stronger reduction (1.7% _v_/_v_) than using these strains separately (0.8-1.0% _v_/_v_) [39]. [PERSON] and [PERSON] (2016) [49] studied the ethanol yield of 91 yeast strains, including some isolates of _S. cerevisiae_ and two commercial strains as control strains.