title: ATP-citrate lyase activity and carotenoid production in batch cultures of Phaffia rhodozyma under nitrogen-limited and nonlimited conditions.
abstract: ATP-citrate lyase (ACL) is the key cytoplasmic enzyme which supplies acetyl-CoA for fatty acids in oleaginous yeast. Although it has been suggested that fatty acid and carotenoid biosynthesis may have a common source of acetyl-CoA in Phaffia rhodozyma, the source for carotenoids is currently unknown. The purpose of this work was to analyze the development of ACL activity during batch cultures of P. rhodozyma under ammonium-limited and nonammonium-limited conditions and study its possible relationship with carotenoid synthesis. Every experiment showed carotenoid accumulation linked to an increasing ACL activity. Moreover, the ACL activity increased with dissolved oxygen (DO), i.e., ACL responded to DO in a similar way as carotenoid synthesis. Additionally, in the ammonium-limited culture, ACL activity increased upon ammonium depletion. However, the contribution to carotenoid accumulation in that case was negligible. This suggests that P. rhodozyma has developed two components of ACL, each one responsive to a different environmental stimulus, i.e., DO and ammonium depletion. The role of each component is still unknown; however, considering that the former responds to DO and the known role of carotenoids as antioxidants, it may be a provider of acetyl-CoA for carotenoid synthesis.
authors.affiliation: Department of Biotechnology and Bioengineering, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, México 07360, DF, México.
authors.forename: Cipriano
authors.initials: C
authors.lastname: Chávez-Cabrera
authors.forename: Zoila R
authors.initials: ZR
authors.lastname: Flores-Bustamante
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Marsch
authors.forename: María del Carmen
authors.initials: Mdel C
authors.lastname: Montes
authors.forename: Sergio
authors.initials: S
authors.lastname: Sánchez
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Cancino-Díaz
authors.forename: Luis Bernardo
authors.initials: LB
authors.lastname: Flores-Cotera
mesh_terms: D001275:ATP Citrate (pro-S)-Lyase / Q000096:biosynthesis*; D000105:Acetyl Coenzyme A / Q000378:metabolism; D001487:Basidiomycota / Q000254:growth & development* / Q000378:metabolism; D002338:Carotenoids / Q000096:biosynthesis*; D005656:Fungal Proteins / Q000096:biosynthesis*; D009584:Nitrogen / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D000644:Quaternary Ammonium Compounds; D002338:Carotenoids; D000105:Acetyl Coenzyme A; D001275:ATP Citrate (pro-S)-Lyase; D009584:Nitrogen