title: Induction of a photomixotrophic plant cell culture of Helianthus annuus and optimization of culture conditions for improved α-tocopherol production.
abstract: Tocopherols, collectively known as vitamin E, are lipophilic antioxidants, which are synthesized only by photosynthetic organisms. Due to their enormous potential to protect cells from oxidative damage, tocopherols are used, e.g., as nutraceuticals and additives in pharmaceuticals. The most biologically active form of vitamin E is α-tocopherol. Most tocopherols are currently produced via chemical synthesis. Nevertheless, this always results in a racemic mixture of different and less effective stereoisomers because the natural isomer has the highest biological activity. Therefore, tocopherols synthesized in natural sources are preferred for medical purposes. The annual sunflower (Helianthus annuus L.) is a well-known source for α-tocopherol. Within the presented work, sunflower callus and suspension cultures were established growing under photomixotrophic conditions to enhance α-tocopherol yield. The most efficient callus induction was achieved with sunflower stems cultivated on solid Murashige and Skoog medium supplemented with 30 g l(-1) sucrose, 0.5 mg l(-1) of the auxin 1-naphthalene acetic acid, and 0.5 mg l(-1) of the cytokinin 6-benzylaminopurine. Photomixotrophic sunflower suspension cultures were induced by transferring previously established callus into liquid medium. The effects of light intensity, sugar concentration, and culture age on growth rate and α-tocopherol synthesis rate were characterized. A considerable increase (max. 230%) of α-tocopherol production in the cells was obtained within the photomixotrophic cell culture compared to a heterotrophic cell culture. These results will be useful for improving α-tocopherol yields of plant in vitro cultures.
authors: Institute of Food Technology and Bioprocess Engineering, Technische Universität Dresden, Bergstraße 120, 01069, Dresden, Germany, katja.geipel@tu-dresden.de.
authors: Katja
authors: K
authors: Geipel
authors: Xue
authors: X
authors: Song
authors: Maria Lisa
authors: ML
authors: Socher
authors: Sibylle
authors: S
authors: Kümmritz
authors: Joachim
authors: J
authors: Püschel
authors: Thomas
authors: T
authors: Bley
authors: Jutta
authors: J
authors: Ludwig-Müller
authors: Juliane
authors: J
authors: Steingroewer
mesh_terms: D001709:Biotechnology / Q000379:methods*; D018929:Cell Culture Techniques / Q000379:methods; D003470:Culture Media / Q000737:chemistry; D005947:Glucose / Q000378:metabolism; D006368:Helianthus / Q000254:growth & development* / Q000378:metabolism*; D008027:Light; D024502:alpha-Tocopherol / Q000378:metabolism*
chemical_list: D003470:Culture Media; D024502:alpha-Tocopherol; D005947:Glucose