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Abstract A novel budding yeast species was isolated from a soil sample collected in the United States of America. Phylogenetic analyses of multiple loci and phylogenomic analyses conclusively placed the species within the genusPichia. Strain yHMH446 falls within a clade that includesPichia norvegensis,Pichia pseudocactophila,Candida inconspicua, andPichia cactophila. Whole genome sequence data were analyzed for the presence of genes known to be important for carbon and nitrogen metabolism, and the phenotypic data from the novel species were compared to allPichiaspecies with publicly available genomes. Across the genus, including the novel species candidate, we found that the inability to use many carbon and nitrogen sources correlated with the absence of metabolic genes. Based on these results,Pichia galeolatasp. nov. is proposed to accommodate yHMH446^T(=NRRL Y‐64187 = CBS 16864). This study shows how integrated taxogenomic analysis can add mechanistic insight to species descriptions. 

Organisms exhibit extensive variation in ecological niche breadth, from very narrow (specialists) to very broad (generalists). Two general paradigms have been proposed to explain this variation: trade-offs between performance efficiency and breadth; and the joint influence of extrinsic (environmental) and intrinsic (genomic) factors. We assembled genomic, metabolic, and ecological data from nearly all known species of the ancient fungal subphylum Saccharomycotina (1,154 yeast strains from 1,051 species), grown in 24 different environmental conditions, to examine niche breadth evolution. We found that large differences in the breadth of carbon utilization traits between yeasts stem from intrinsic differences in genes encoding specific metabolic pathways, but limited evidence for trade-offs. These comprehensive data argue that intrinsic factors shape niche breadth variation in microbes.