| 20080299625 | Microbial Strains Producing Sphingoid Bases or Derivatives Thereof - The present invention provides microbial strains, in particular yeast strains, that produce at least 0.1 mg per g biomass dry weight of a sphingoid base. The present invention further provides a method to obtain sphingoid base-producing microbial strains comprising incubating a population of microbial cells in the presence of a suitable concentration of a toxin, selecting cells that are resistant against said toxin, and isolating cells out of the toxin-resistant cell population that produce at least 0.1 mg per g biomass dry weight of the sphingoid base of Formula I. Optionally, the method further comprises subjecting a population of toxin-resistant microbial cells that produce at least 0.1 mg per g biomass dry weight of the sphingoid base of Formula I to DNA-mediated transformation with a polynucleotide encoding an enzyme of the sphingolipid metabolic pathway. The present invention further provides a polypeptide having dihydroceramide desaturase activity obtainable form Pichia ciferrii. | 12-04-2008 |