Alcohol-conferred hemolysis in yeast is a consequence of increased respiratory burden.
We have previously reported that growth on alcohol vapors confers hemolytic properties on certain yeast species and strains ('microbial alcohol conferred hemolysis'; MACH). Here, a Saccharomyces cerevisiae deletion library consisting of c. 4800 clones was screened for MACH mutants in the presence of n-butanol vapors; 136 mutants were MACH-negative, and 325 exhibited reduced hemolysis and/or growth. Of the MACH-negative mutants, 35.3% were affected in mitochondrial-related genes. The data suggest that intact mitochondrial and respiratory chain functions are critical for the observed MACH phenomenon. We propose that the uncontrolled cellular uptake of alcohol results in yeast 'hyper-respiration', leading to elaboration of hemolytic molecules such as hydrogen peroxide and hemolysis-causing lipids. To support this premise, we showed that: (1) exogenous catalase and glutathione reduce alcohol-conferred hemolysis in S. cerevisiae BY4741 and Candida tropicalis 59445; (2) C. tropicalis produces hydrogen peroxide following growth on ethanol and n-butanol, as shown using xylenol orange; and (3) a lysophospholipid-containing lipid extract from alcohol-grown C. tropicalis specifically causes hemolysis.
Shuster
Amir
A
Department of Human Microbiology, Sackler Faculty of Medicine, Tel-Aviv University, Ramat-Aviv, Israel.
Osherov
Nir
N
Leikin-Frenkel
Alicia
A
Rosenberg
Mel
M
D000438:Alcohols / Q000494:pharmacology*; D002374:Catalase / Q000378:metabolism; D003580:Cytochromes / Q000032:analysis; D003576:Electron Transport Complex IV / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005978:Glutathione / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000633:toxicity; D008246:Lysophospholipids / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010101:Oxygen Consumption / Q000187:drug effects; D010636:Phenols; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D013454:Sulfoxides; D014992:Xylenes / Q000378:metabolism
D000438:Alcohols; D003580:Cytochromes; D008246:Lysophospholipids; D010636:Phenols; D029701:Saccharomyces cerevisiae Proteins; D013454:Sulfoxides; D014992:Xylenes; D006861:Hydrogen Peroxide; D002374:Catalase; D003576:Electron Transport Complex IV; D005978:Glutathione; C016833:xylenol orange