Construction of a novel Pichia pastoris strain for production of xanthophylls
1 Department of Microbiology, University of Santiago de Compostela, Santiago de Compostela, Spain
2 School of Biotechnology, University of Santiago de Compostela, Santiago de Compostela, Spain
3 Discipline of Physiology and Bosch Institute, University of Sydney, Sydney, NSW, 2006, Australia
AMB Express 2012, 2:24 doi:10.1186/2191-0855-2-24Published: 25 April 2012
In this study, we used the yeast carotenogenic producer Pichia pastoris Pp-EBIL strain, which has been metabolically engineered, by heterologously expressing β-carotene-pathway enzymes to produce β-carotene, as a vessel for recombinant astaxanthin expression. For this purpose, we designed new P. pastoris recombinant-strains harboring astaxanthin-encoding genes from carotenogenic microorganism, and thus capable of producing xanthophyllic compounds. We designed and constructed a plasmid (pGAPZA-WZ) containing both the β-carotene ketolase (crtW) and β-carotene hydroxylase (crtZ) genes from Agrobacterium aurantiacum, under the control of the GAP promoter and containing an AOX-1 terminator. The plasmid was then integrated into the P. pastoris Pp-EBIL strain genomic DNA, producing clone Pp-EBILWZ. The recombinant P. pastoris (Pp-EBILWZ) cells exhibited a strong reddish carotenoid coloration and were confirmed, by HPLC, to produce not only the previous described carotenoids lycopene and β-carotene, but also de novo synthesized astaxanthin.