Figure 5. Fermentation
phenotypes in N. atacamensis . A . Growth rate
under glucose, fructose and sucrose 2% w/v, and glucose 20% w/vas
carbon sources. B . Growth rates under medium supplemented with
glucose 2% w/v and ethanol at 6 and 8% v/v. Fermentation results in
Synthetic Wine Must (SWM) with a YAN concentration of 300 mg/mL.C . CO2 loss, D . Sugar consumption, E. Ethanol
production and F . Glycerol production. EC1118 (grey dots) andN. atacamensis (orange dots).
Based on the results obtained from the microcultures, we proceeded to
conduct wine fermentations using monocultures of the N.
atacamensis type strain. To assess its fermentation capability, we
measured the amount of CO2 lost under Synthetic Wine
Must (SWM) conditions, with a YAN concentration of 300 mg/mL. The
fermentation assay revealed that ATA-11A-BT was
capable of fermenting SWM, achieving a maximum of 75,5 g/L, which was
significantly lower compared to the commercially available S.
cerevisiae control strain (p -value < 0.05, one-way
ANOVA, Figure 5C ). The N. atacamensis type strain
exhibited incomplete fermentation (Figure 5D ), producing
ethanol levels of 7.3 ± 0.4% v/v (Figure 5E ) and a having a
residual sugar content of 126.7 g/L, comprising 25.8 ± 7.0 g/L of
glucose and 100.9 ± 2.5 g/L of fructose (Figure 5D ). In
contrast, the EC1118 control demonstrated a higher ethanol and glycerol
production (Figure 5F ), reaching up to 14.4 ± 0.2% v/v of
ethanol, with only 23.6 ± 2.4 g/L of residual fructose (Table
S8 ). Nevertheless, it is important to note that these values are
comparable to those observed with other non-conventional yeasts used in
the wine industry, such as Torulaspora delbrueckii ,Metschnikowia pulcherrima , Starmerella bacillaris ,Wickerhamomyces anomalus and Hanseniaspora vineae(Vejarano & Gil-Calderón, 2021). Altogether, our findings suggest the
potential utilization of the novel species N. atacamensis in
monocultures or in co-cultures with S. cerevisiae for wine
fermentation.