Creation of Hansenula polymorpha fatty acid auxotrophic mutants for genetic study of fatty acid biosynthesis

Three groups of Hansenula polymorpha fatty acid auxotrophic mutants were screened by their fatty acid requirement for growth. The mutants are saturated fatty acid auxotrophic mutants (Sfa - ), monounsaturated fatty acid auxotrophic mutants (Mfa - ) and polyunsaturated fatty acid auxotrophic mutants (Pfa - ) which required saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids, respectively. All Sfa - mutants could grow on the media supplemented with C14:0 but not grow on the media with neither C16:0 nor C18:0. By fatty acid analysis, two of the Sfa - mutants, S7 and S16, showed a significant difference in the fatty acid composition. S7 clearly defected in the production of C18:2Δ9,12 and C18:3Δ9,12,15, while S16 significantly accumulated medium-chain saturated fatty acids, C12:0 and C14:0.  Mfa - and Pfa - mutants could grow on the media supplemented with monounsaturated fatty acids better than supplemented with polyunsaturated fatty acids. The mutants obtained in this study could be used as tools for studying in genes involved in the fatty acid synthesis and biological effect of fatty acids.