Canna~Fangled Abstracts Production of Δ9-tetrahydrocannabinolic acid from cannabigerolic acid by whole cells of Pichia (Komagataella) pastoris expressing Δ9-tetrahydrocannabinolic acid synthase from Cannabis sativa L. 2015 May 21. Zirpel B1, Stehle F, Kayser O. Author information Abstract OBJECTIVE: The Δ9-tetrahydrocannabinolic acid synthase (THCAS) from…Freedom WaresMay 21, 2015