Oleaginous yeasts: Time to rethink the definition?

Area of Science:

• Biotechnology
• Microbiology
• Synthetic Biology

Background:

• Oleaginous yeasts accumulate >20% dry weight as lipids, driving interest in sustainable oleochemicals.
• Yarrowia lipolytica is a prominent model, but novel oleaginous yeasts, including Saccharomyces cerevisiae strains, are emerging.
• Current definitions focus on triacylglyceride accumulation, limiting scope.

Purpose of the Study:

• To critically analyze the definition of 'oleaginous yeast'.
• To propose an expanded definition encompassing intracellular/extracellular lipid production.
• To clarify terminology for Yarrowia lipolytica and other yeasts.

Main Methods:

• Literature review and critical analysis of existing definitions.
• Comparative analysis of lipid accumulation capabilities across yeast species.
• Examination of metabolic adaptations in lipid synthesis and storage.

Main Results:

• The term 'oleaginous yeast' is primarily of biotechnological value, not a distinct taxonomic or phylogenetic classification.
• Proposed expanded definition: yeasts producing intracellular or extracellular lipids under any growth condition.
• Yarrowia lipolytica exhibits both lipophilic and oleaginous phenotypes, necessitating strain-specific designation.

Conclusions:

• The definition of oleaginous yeast should be broadened to include diverse lipid production.
• The term 'oleaginous' should apply to specific strains, not entire species.
• Refined definitions will enhance research and biotechnological applications of yeasts for lipid production.