Production of biomass and bioactive compounds from shoot cultures of Rosa rugosa using a bioreactor culture system

Rosa rugosa Thunb. is a popular ornamental and medicinal plant native to eastern Asia. In this study, a successful bioreactor culture system was established for the production of secondary metabolites of rugosa roses. We tested different concentrations and combinations of plant hormones in growth media for maximum shoot proliferation and production of bioactive compounds, different bioreactor systems for maximum biomass production and production of bioactive compounds, and different ratios of nitrogen sources for maximum shoot growth and accumulation of bioactive compounds. For multiple shoot proliferation, Murashige and Skoog (MS) medium was used, supplemented with different concentrations and combinations of plant hormones: 6-benzylaminopurine (BA; 0-13.2 A mu M), thidiazuron (TDZ; 0-13.5 A mu M), and indole butyric acid (IBA) at 2.5 A mu M, used alone or in a combination of IBA with BA or TDZ. Rapid micropropagation of multiple shoots of rugosa roses was successfully achieved using shoot tips explanted in semisolid MS medium supplemented with 4.4 A mu M BA. The average number of shoots grown was 15.6 per explant and the maximum shoot length was 2.7 cm at 8 weeks of culture. To investigate the effect of nitrogen sources on shoot growth and bioactive compound accumulation, shoots were treated with different ratios of nitrogen sources (NH4 (+):NO3 (-)) for 1 week after 7 weeks of shoot culture. Next, to scale up biomass production for the generation of useful phytochemicals, multiple-shoot cultures were developed in large-scale bioreactors. Four bioreactor systems were used: continuous immersion bioreactor (CIB), continuous immersion bioreactor with net (CIB-N), temporary immersion bioreactor (TIB), and temporary immersion bioreactor with net (TIB-N). Solid and liquid media were used as controls. Of the different bioreactor types, the CIB system produced the highest biomass, followed by the TIB system. Multiple shoots grown in the CIB system resulted in the accumulation of 39.21 mg center dot g(-1) dry weight (DW) of total phenolics and 13.28 mg center dot g(-1) DW of total flavonoids. The productivity of total phenolics and flavonoids was highest in the shoots harvested from the CIB system. The results of this study suggest that multiple shoots of rugosa roses can be used in commercial-scale bioreactors to produce useful bioactive compounds for the pharmaceutical and cosmetic industries.