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Alcohol-conferred hemolysis in yeast is a consequence of increased respiratory burden

Amir Shuster1, Nir Osherov, Alicia Leikin-Frenkel

  • 1Department of Human Microbiology, Sackler Faculty of Medicine, Tel-Aviv University, Ramat-Aviv, Israel.

FEMS Yeast Research
|June 15, 2007
PubMed

Insights

Yeast grown in alcohol vapors can cause red blood cell lysis, a phenomenon known as microbial alcohol conferred hemolysis (MACH). Intact mitochondrial function is crucial for MACH, suggesting hyper-respiration leads to the production of hemolytic molecules like hydrogen peroxide.

Area of Science:

  • Microbiology
  • Biochemistry
  • Yeast Genetics

Background:

  • Certain yeast species exhibit hemolytic properties when grown in alcohol vapors, a process termed microbial alcohol conferred hemolysis (MACH).
  • The genetic and molecular basis underlying MACH is not fully understood.

Purpose of the Study:

  • To identify genes and cellular processes critical for MACH using a large-scale genetic screen.
  • To elucidate the mechanism by which alcohol vapors induce yeast hemolysis.

Main Methods:

  • Screened a Saccharomyces cerevisiae deletion library (approx. 4800 mutants) for defects in MACH using n-butanol vapors.
  • Analyzed MACH-negative and reduced-hemolysis mutants for affected genes, focusing on mitochondrial function.
  • Investigated the role of hydrogen peroxide and lipids in MACH using biochemical assays and extracts.

Main Results:

  • Identified 136 MACH-negative and 325 reduced-hemolysis/growth mutants.
  • 35.3% of MACH-negative mutants were associated with mitochondrial or respiratory chain genes.
  • Exogenous catalase and glutathione reduced MACH; Candida tropicalis produced hydrogen peroxide and hemolytic lipids upon alcohol growth.

Conclusions:

  • Intact mitochondrial and respiratory chain function are essential for the MACH phenomenon.
  • Alcohol-induced 'hyper-respiration' in yeast likely leads to the production of hemolytic molecules.
  • Hydrogen peroxide and specific lipids are key mediators of alcohol-conferred hemolysis in yeast.

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