Figure 4. 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 4C ). The N. atacamensis type strain
exhibited incomplete fermentation, producing ethanol levels of 7.3 ±
0.4% v/v 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. In contrast,
the EC1118 control demonstrated a higher ethanol production, reaching up
to 14.4 ± 0.2% v/v, 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. cerevisiaefor wine fermentation.