title: Vitamin E (alpha-tocopherol) production by the marine microalgae Dunaliella tertiolecta and Tetraselmis suecica in batch cultivation.
abstract: Batch experiments with Dunaliella tertiolecta and Tetraselmis suecica were performed to investigate alpha-tocopherol (alpha-T) production in time, in order to assess the effect of light availability per cell on the production of this antioxidant. In D. tertiolecta alpha-T content increased during growth, in other words, as the cell density increased and the light availability per cell decreased. In T. suecica the pattern was different: alpha-T content was highest during the exponential phase, decreased significantly during the linear phase and increased again towards the end of the cultivation. Chlorophyll (chl-a) content of T. suecica cells decreased after the exponential phase, instead of the expected increase typically observed in shade-adapted cells, suggesting that the culture was nutrient limited. An experiment with extra nutrients showed that chl-a and alpha-T content increased significantly during both the linear and the stationary phase when compared with values in nutrient-deficient conditions. No correlation between alpha-T and chl-a was observed. Our results indicate that diminished light availability does not limit alpha-T production in D. tertiolecta and T. suecica, opening up the possibility of using high cell density, light-limited cultures for the production of this commercially interesting compound.
authors.affiliation: Food and Bioprocess Engineering Group, Department of Agrotechnology and Food Sciences, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands. eira.carballo@wur.nl
authors.forename: Eira C
authors.initials: EC
authors.lastname: Carballo-Cárdenas
authors.forename: Pham Minh
authors.initials: PM
authors.lastname: Tuan
authors.forename: Marcel
authors.initials: M
authors.lastname: Janssen
authors.forename: René H
authors.initials: RH
authors.lastname: Wijffels
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology / Q000528:radiation effects; D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D002455:Cell Division / Q000502:physiology / Q000528:radiation effects; D002478:Cells, Cultured; D002734:Chlorophyll / Q000378:metabolism*; D000077194:Chlorophyll A; D000460:Chlorophyta / Q000166:cytology / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D009566:Nitrates / Q000378:metabolism*; D011829:Radiation Dosage; D013045:Species Specificity; D024502:alpha-Tocopherol / Q000378:metabolism*
chemical_list: D009566:Nitrates; D002734:Chlorophyll; C031618:sodium nitrate; D024502:alpha-Tocopherol; D000077194:Chlorophyll A