Bioreactor type affects the accumulation of phenolic acids and flavonoids in microshoot cultures of Schisandra chinensis (Turcz.) Baill

Microshoots of the East Asian medicinal plant species Schisandra chinensis (Chinese magnolia vine) were grown in bioreactors characterized by different construction and cultivation mode. The tested systems included two continuous immersion systems-a cone-type bioreactor (CNB) and a cylindric tube bioreactor (CTB), a nutrient sprinkle bioreactor (NSB), and two temporary immersion systems (TIS)-RITA® and Plantform. Microshoots were grown for 30 and 60 days in the MS medium enriched with 1 mg $1^{-1}$ NAA and 3 mg $1^{-1}$ BA. The accumulation of two groups of phenolic compounds: phenolic acids and flavonoids in the bioreactor-grown S. chinensis biomass, was evaluated for the first time. In the microshoot extracts, seven phenolic acids: chlorogenic, gallic, p-hydroxybenzoic, protocatechuic, syringic, salicylic and vanillic, and three flavonoids: kaempferol, quercitrin and rutoside, were identified. The highest total amount of phenolic acids (46.68 mg 100 $g^{-1}$ DW) was recorded in the biomass maintained in the CNB for 30 days. The highest total content of flavonoids (29.02 mg 100 $g^{-1}$ DW) was found in the microshoots maintained in the NSB for 30 days. The predominant metabolites in all the tested systems were: gallic acid (up to 10.01 mg 100 $g^{-1}$ DW), protocatechuic acid (maximal concentration 16.30 mg 100 $g^{-1}$ DW), and quercitrin (highest content 21.00 mg 100 $g^{-1}$ DW)