Yeast species and strains differing along an altitudinal gradient in the Brazilian forest domain

Abstract

Soil microbiota is an important component of the forest biomes, playing important roles in the soil aggregation and cycling of nutrients. Among the soil microorganisms stand out the yeasts, which are unicellular fungi involved in important soil ecological processes. The Brazilian Atlantic Forest is one of the main biodiversity hotspots in the world, and the effect of altitudinal gradient on the distribution patterns of yeast species across this ecosystem has not yet been addressed. Thus, this study aimed to investigate the occurrence and distribution of yeast species in soils along an altitude gradient (404; 1,016; 1,658; and 2,124 m above the sea level) of Serra dos Órgãos National Park located at Rio de Janeiro State, Brazil. Yeast species were described using a culture-based method. Species identification was performed using the fungal barcode locus, the D1/D2 region of 26S rRNA, and the gene genealogy was used to access the intraspecific distribution of strains along the altitudinal gradient. We isolated and identified a total of 76 yeasts including ten species belonging to eight genera. Basidiomycetes predominated over ascomycetes. Saitozyma podzolica and Meyerozyma guilliermondii were isolated at all altitudes. The principal component analysis showed that 88 % of sample distribution is explained by soil properties. For S. podzolica, the genetic genealogy suggested that intraspecific distribution is likely related to similar altitudes. Overall, the species composition and soil properties were modified as altitude was increasing, being more heterogeneous and richness in high altitudes.

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“…Serial dilutions of this honey mixture were prepared using sterile distilled water. Following dilution, 100 l of each dilution were evenly spread onto YM Agar (0,5% peptone; 0,3% yeast extract; 0,3% malt extract; 1% glucose; 2,0% agar), supplemented with 100 mg/L chloramphenicol to suppress bacterial growth 16 . The prepared plates were incubated at 30°C and monitored periodically.…”

“…The ubiquitous species M. guilliermondii has demonstrated its ability to endure high altitudes during coffee fermentation, and can be found at elevations ranging from 300 to higher than1800 meters above sea level 16,27 .…”

Maize-associated Meyerozyma from the Brazilian semiarid region are effective plant growth-promoting yeasts

“…Twelve out of the thirteen strains were closest to M. guilliermondii CBS 2030 T and ESA 35 to M. caribbica CBS 9966 T (99.64%), and M. carpophila CBS 5256 T . Meyerozyma yeasts are ubiquitously distributed in the environment, inhabiting rhizospheres, bulk soils, and plant tissues (Moreira et al, 2020;Moreira and Vale, 2018;Nakayan et al, 2013;Peng et al, 2018). Despite the absence of reports for Brazil, in C4 grasses this genus was already isolated from maize rhizosphere in Mexico (Sarabia et al, 2018), in addition to maize and sugarcane (Saccharum spp.)…”