Pichia ciferrii cell, characterized in that the cell has, compared to its wild type, a reduced activity of at least one of the enzymes which are encoded by the intron-free nucleic acid sequences selected from the two groups A) and B) consisting of A) Seq ID No 1, Seq ID No 3, Seq ID No 5, Seq ID No 7, Seq ID No 9, Seq ID No 11, B) a sequence which is at least 80% identical to any of the sequences Seq ID No 1, Seq ID No 3, Seq ID No 5, Seq ID No 7, Seq ID No 9, Seq ID No 11, characterized in that the reduced activity of at least one of the enzymes represents a combination of reduced activities of the enzymes selected from the group: Seq ID No 3 or its group B analogue; Seq ID No 5 or its group B analogue; Seq ID No 7 or its group B analogue; Seq ID No 9 or its group B analogue; Seq ID No 11 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 7 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 11 or its group B analogue and Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 7 or its group B analogue and Seq ID No 11 or its group B analogue. A) Seq ID No 1, Seq ID No 3, Seq ID No 5, Seq ID No 7, Seq ID No 9, Seq ID No 11, B) a sequence which is at least 80% identical to any of the sequences Seq ID No 1, Seq ID No 3, Seq ID No 5, Seq ID No 7, Seq ID No 9, Seq ID No 11, characterized in that the reduced activity of at least one of the enzymes represents a combination of reduced activities of the enzymes selected from the group: Seq ID No 3 or its group B analogue; Seq ID No 5 or its group B analogue; Seq ID No 7 or its group B analogue; Seq ID No 9 or its group B analogue; Seq ID No 11 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 7 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 11 or its group B analogue and Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 7 or its group B analogue and Seq ID No 11 or its group B analogue. Seq ID No 3 or its group B analogue; Seq ID No 5 or its group B analogue; Seq ID No 7 or its group B analogue; Seq ID No 9 or its group B analogue; Seq ID No 11 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 7 or its group B analogue; Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 11 or its group B analogue and Seq ID No 1 or its group B analogue and Seq ID No 3 or its group B analogue and Seq ID No 5 or its group B analogue and Seq ID No 7 or its group B analogue and Seq ID No 11 or its group B analogue.