Patent ID: 8609371

Claim:
A nucleic acid molecule that encodes a variant squalene synthase enzyme, wherein the variant enzyme comprises one or more amino acid substitutions in the squalene synthase enzyme whose sequence is set forth in SEQ ID NO: 4, and comprises a sequence of amino acid residues that is at least 95% identical to the squalene synthase enzyme whose sequence is set forth in SEQ ID NO: 4, whereby: the variant enzyme exhibits reduced cellular squalene synthase activity compared to the enzyme that does not comprise the one or more amino acid substitution(s); the variant enzyme, when present and expressed in vivo in a eukaryotic microbial host as the only squalene synthase species, catalyzes the synthesis of squalene at a sufficiently high rate that supplementation of the eukaryotic microbial host with a sterol is not required for growth; and the eukaryotic microbial host produces a terpene product in medium lacking a sterol.