Metabolic flux analysis of the two astaxanthin-producing microorganisms Haematococcus pluvialis and Phaffia rhodozyma in the pure and mixed cultures.
The two major astaxanthin-producing microorganisms Phaffia rhodozyma and Haematococcus pluvialis exhibited elevated astaxanthin yields under the mixed culture regime, and the changes in flux distribution were investigated by means of metabolic flux analysis (MFA). In the mixed culture of the two strains, the carbon flux towards astaxanthin formation in P. rhodozyma increased by 20%, which may be due to the enriched oxygen evolved through the photosynthesis of H. pluvialis. On the other hand, the uptake of pyruvate and CO(2) excreted by P. rhodozyma also facilitated astaxanthin synthesis in H. pluvialis, which reduced 33% of the carbon flux exported from Calvin cycle to the catabolic pathway, and in turn raised the carbon flux to glyceraldehyde-3-phosphate by 25%. As a result, the carbon flux diverted to astaxanthin synthesis increased 2.8-fold in comparison with that in the pure culture.
Dong
Qing-Lin
QL
Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin, PR China.
Zhao
Xue-Ming
XM
Ma
Hong-Wu
HW
Xing
Xiang-Ying
XY
Sun
Nai-Xia
NX
D000818:Animals; D001487:Basidiomycota / Q000378:metabolism*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002245:Carbon Dioxide / Q000737:chemistry; D018929:Cell Culture Techniques / Q000379:methods; D000460:Chlorophyta / Q000378:metabolism*; D007218:Industrial Microbiology / Q000379:methods*; D008956:Models, Chemical; D010100:Oxygen / Q000378:metabolism; D010788:Photosynthesis; D013997:Time Factors; D024341:Xanthophylls / Q000737:chemistry
D024341:Xanthophylls; D002245:Carbon Dioxide; C005948:astaxanthine; D010100:Oxygen