Cistanche Deserticola Cell Cultures And Process Metabolic Regulation

The kinetics of cell cultures of Cistanche deserlicola (C. deserlicola), the effect of yeast, chitosan and osmotic pressure on phenylethanoid glycosides (PeGs) accumulation and antioxidant activity of C. deserticola were investigated. It is a fundamental work for the large-scale production of bioactive compounds using C.deserticola cell cultures.The optimal conditions for the callus growth and PeGs formation of was at 25 ℃ without light on solidified MS media supplemented with 1.0 mg NAA/l , 2.0 mg 6-BA /l , 0.25 mg 2, 4- D /l and 30 g sucrose/1. When the inoculation size was 3%, the dry weight (DW) and PeGs production reached 8 g /l medium and 56.9 mg/l after 30 days culture. DW and PeGs production reached 8.1 g /l medium and 97.3 mg/1 after 21 days culture. In the cell suspension culture, 0-3 d was lag phase, 3-18 d was exponential phase and 18-30 d was stationary phase.The results showed that cell growth and PeGs accumulation were enhanced by addition of yeast elicitor. Yeast elicitor repeatedly added on days 15, 17 and 19 at the dose of 106 mg total sugar/1 medium improved PeGs accumulation further, and the final PeGs content and production reached 31.3 mg/g DW and 317.8 mg/1, which were 195%and 235% that of the control, respectively. Addition of chitosan slightly inhibited cell growth whereas stimulated PeGs synthesis. Chitosan repeatedly added on days 15 and 17 at the dose of 10 mg/1 medium improved PeGs synthesis further, and the final PeGs content and production reached 43.6 mg/g DW and 364.6 mg/l, which were 272 % and 270% that of the control, respectively.Effect of osmotic pressure on PeGs accumulation was investigated. The results showed that high initial sugar concentration was beneficial for both growth and PeGs synthesis. However, a longer growth phage was also seen. Other osmotic agents such as manitol and PEG also showed similar stimulation effect on PeGs synthesis. The strategy of sucrose and mannitol feeding dramatically stimulated cell growth and PeGs accumulation. 30 g/l sucrose and 20 g/l mannitol feeding in the 12th day of the culture gave the highest PeGs content and production.Antioxidant activities of wild C. deserlicola and callus and cell cultures of C. deserticola were investigated according to the method of DPPH. Cell cultures showed stronger antioxidant activity than wild C. deserticola. Antioxidant activity of PeGs extracted from C. deserticola was slightly lower than that of Vitamin C and PeGs is an attractive resource of natural antioxidant.