High prevalence of L. cidri among
non-Saccharomyces yeasts in natural environments
To explore the distribution of L. cidri in central and southern
Chile, we obtained yeast colonies from tree bark samples collected
between 2017 and 2019 that had been previously identified as
non-Saccharomyces (Nespolo et al., 2020b) using the internal
transcribed spacer region (ITS1-5.8rRNA-ITS2 ). Colonies
identified as L. cidri were found in 7 of the 13 sampling
regions, between Altos de Lircay National Park (VII Maule Region, Chile)
in the north and Coyhaique National Reserve (XI Aysén Region, Chile) in
the south. Moreover, the distribution of L. cidri were
widely-distributed in South Chile, covering regions from the Pacific
coast up to the Andes Mountains (approximately 1,000 km long and 300 km
wide) (Fig 1a, Table S4). Overall, we identified 30 L. cidristrains in Patagonia, meaning that L. cidri is the
most-represented non-conventional ethanol-tolerant species in our
survey. The L. cidri isolation frequency varied between 1.33 to
11.11 % depending on the national park, independent of latitude
(Pearson r = -0.338, p -value > 0.05) (Fig S1a, Table
S4). In addition, when only non-Saccharomyces yeasts were
considered, the isolation frequency values varied between 9.72-100 %
(Fig. S1b, Table S4), indicating a high prevalence of this
non-conventional yeast in Nothofagus bark samples. The samples
from Chile were obtained in four different tree species, N.
pumilio (representing 26.7 % of the samples), N. dombeyi (46.7
%), N. antartica (3.3 %), and A. araucana (23.3 %)
(Fig. S1c). The frequency of L. cidri in Patagonia was determined
by the host tree (hypergeometric test, Table S5); N. dombeyi was
the most prevalent host. Additionally, colonies identified as L.
cidri were obtained in a previous study from eucalyptus tree sap
samples collected in the Central Plateau of Tasmania, Australia (Varela
et al., 2020) (Fig. 1a). In this case, L. cidri represented 13%
of the total non-Saccharomyces colonies found. Unlike Patagonia,
all L. cidri isolates in Australia were obtained from E.
gunnii in rich culture media without ethanol. Thus, for further
analysis, we randomly selected 25 colonies from different tree sap
samples. Altogether, our results demonstrate a high prevalence ofL. cidri in Patagonia and Australia, with a wide distribution
from high altitude (Andes Mountains) to low altitude regions (near the
Pacific Ocean), covering an extensive range of niches and environmental
conditions.