Deletion of genes encoding fatty acid desaturases leads to alterations in stress sensitivity in Pichia pastoris

FEMS Yeast Res. 2015 Jun;15(4):fov020. doi: 10.1093/femsyr/fov020. Epub 2015 Apr 22.


Unsaturated fatty acids (UFAs) are key compounds which have important roles in maintaining cell membrane physiological functions and the adaption to tough conditions. Defects of fatty acid desaturases will change cellular UFA constitution. Pichia pastoris GS115 has four fatty acid desaturase genes, namely FAD9A, FAD9B, FAD12 and FAD15. Their products catalyze the synthesis of three kinds of UFAs, oleic acid (catalyzed by Fad9A and Fad9B), linoleic acid (catalyzed by Fad12) and α-linolenic acid (catalyzed by Fad15), respectively. In this study, we found that deletion of FAD12 led to increased resistance to oxidative stress. Cellular lipid peroxidation levels declined in the fad12Δ mutant upon H2O2 treatment. Cellular fatty acids compositions were changed with the increased expression of FAD9A. On the other hand, deletion of FAD9A resulted in increased tolerance to the plasma membrane (PM) damage agent SDS, and PM deformation was not detected in the fad9AΔ mutant under this stress. Our results showed that UFAs are related to cell adaption to adverse environmental changes.

Keywords: Pichia pastoris; fatty acid desaturase; oxidative stress; plasma membrane damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fatty Acid Desaturases / genetics
  • Fatty Acid Desaturases / metabolism*
  • Fatty Acids, Unsaturated / metabolism*
  • Gene Deletion*
  • Hydrogen Peroxide / toxicity
  • Lipid Peroxidation
  • Oxidative Stress*
  • Pichia / enzymology*
  • Pichia / genetics
  • Pichia / metabolism
  • Pichia / physiology*
  • Sodium Dodecyl Sulfate / toxicity
  • Stress, Physiological*


  • Fatty Acids, Unsaturated
  • Sodium Dodecyl Sulfate
  • Hydrogen Peroxide
  • Fatty Acid Desaturases