Phytochemical composition, biological activity and genetic variability of red and yellow muscadine cell lines in bioreactor cultivation

Muscadine grapes [Muscadinia rotundifolia (Michx.) Small.] are the most economically important cultivated grapes in the Southeastern part of the United States. These unique native American grapes could be distinguished from the other Vitis species not only by their specific morphologic and organoleptic properties by also by their increased chromosomal numbers specific photochemical patterns, remarkable phytopathogen resistance, and elevated production of health beneficial compounds. In this study, we have used different nutrient media (B5 and LS), to initiate two types of cell lines (red and yellow colored) which originated from super-epidermal cells of physiologically mature berry of Muscadinia 'Noble'. The suspensions were cultivated in submerged flasks, and stirred tank bioreactor. The produced biomasses were analyzed for anthocyanin, flavonoid and phenolic contents, as well as for antioxidant activities (DPPH, TEAC. FRAP and CUPRAC methods). In addition, acetylcholinesterase inhibitory activities (Ellman's method) were evaluated as well. The yellow cell line showed better growth characteristics, compared to the red one (ADB = 7.11 +/- 0.27 g DW L-1 and GI = 10.21 +/- 0.38, vs. ADB = 4.44 +/- 0.71 g DW L-1 and GI = 4.87 +/- 0.78), whereas only the red suspension produced anthocyanins (TA = 2.49 +/- 0.08 mg Pet-3,5 E L-1). The existence of polymorphism among the two suspension cultures, triggered by the nutrient medium composition and the cultivation conditions, was analyzed by 10 random amplified polymorphic DNA (RAPD) and 10 simple sequence repeat (SSR) markers. To our knowledge, this is the first report for submerged cultivation of muscadine cell suspensions in different cultivation systems. The newly generated data for the role of nutrient medium composition on genetic variability, photochemical composition and biological activities of in vitro cultivated muscadine cell cultures forms the base for future research on both optimization of in vitro cultivation conditions and deeper understanding of regulatory mechanisms, controlling primary and secondary biosynthesis of metabolites in muscadine grape.