Genomic factors shape carbon and nitrogen metabolic niche breadth across Saccharomycotina yeasts.

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: (i) trade-offs between performance efficiency and breadth and (ii) 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 (1154 yeast strains from 1051 species), grown in 24 different environmental conditions, to examine niche breadth evolution.

Genomic and ecological factors shaping specialism and generalism across an entire subphylum.

Organisms exhibit extensive variation in ecological niche breadth, from very narrow (specialists) to very broad (generalists). Paradigms proposed to explain this variation either invoke trade-offs between performance efficiency and breadth or underlying intrinsic or extrinsic factors. We assembled genomic (1,154 yeast strains from 1,049 species), metabolic (quantitative measures of growth of 843 species in 24 conditions), and ecological (environmental ontology of 1,088 species) data from nearly all known species of the ancient fungal subphylum Saccharomycotina to examine niche breadth evolution.

Repeated horizontal gene transfer of GALactose metabolism genes violates Dollo's law of irreversible loss.

Dollo's law posits that evolutionary losses are irreversible, thereby narrowing the potential paths of evolutionary change. While phenotypic reversals to ancestral states have been observed, little is known about their underlying genetic causes. The genomes of budding yeasts have been shaped by extensive reductive evolution, such as reduced genome sizes and the losses of metabolic capabilities.

. sp. nov., a novel yeast species isolated from subsoil groundwater contaminated with hydrocarbons and from a human infection.

Yeast strains belonging to a novel anamorphic yeast species were isolated from subsoil groundwater contaminated with hydrocarbons in a metal working factory located in northern Spain, and from a human infection in the USA. Comparison of ITS sequences between the isolates revealed 0.2 % divergence between the Spanish isolates and 0.

Screening for Oily Yeasts Able to Convert Hydrolysates from Biomass to Biofuels While Maintaining Industrial Process Relevance.

Research has recently intensified to discover new oleaginous yeast strains able to function quickly and efficiently in low-cost lignocellulosic hydrolysates to produce high-quality lipids for use in biodiesel and chemicals. Detailed techniques are given here for ranking candidate yeast strains based on conversion of hydrolysate sugars to lipids and then optimizing cultivation conditions for best performers in a 96-well aerobic microcultivation format. A full battery of assays applicable to high throughput of small-volume samples are described for efficiently evaluating cell biomass production, lipid accumulation, fatty acid composition, and sugar utilization.