Bioreactor Culture Of Adventitious Roots And Antioxidation Activity Of Oplopanax Elatus

Oplopanax elatus is one of the specific Chinese medicinal materials in Changbai Mountain and has a very high medicinal value. The wild resource of Oplopanax elatus is extinct nearly due to its long growth period, difficulties of seeds propagation and mass collection of wild resoures by people. In order to establish bioreactor culture system of adventitious roots (AR) in O.elatus, we used the seeds of wild plants to induce AR and selected suitable culture medium and conditions of bioreactor culture for AR. To study antioxidant activity of AR, we analysed contents of polysaccharides and phenol compouds, and measured DPPH savgering rate of extracts of polysaccharides and phenol compouds.For selecting suitable culture medium of AR, the effects of MS strength, IBA concentrations, sugar types and concentrations on AR growth were studied, the results showed that AR growth was favorable when MS medium was suplemented by3mg·L-1or4mg·L-1IBA during suspension culture, but3mg·L-1IBA was more optimal in bioreactor culture. White sugar and sucrose were suitable than glucose and fructose, because of lower cost in white sugar, so we can use low-cost white sugar instead of high-priced chemical sucrose to apply in large-scale production of O. elatus adventitious roots. We studied the white sugar concentration, the result showed adventitious root biomass reached the highest value in50g·L-1white sugar.We researched aeration volume and inoculation density of adventitious roots in bioreactor culture, then found that a5L air-lift bioreactor with4L medium added20g (fresh weight) of adventitious roots was significantly better than inoculation density treatment of10g,30g and40g. Aeration volume had a great influence on adventitious root growth in the airlift bioreactor, too much or too little aeration volume was not conducive to adventitious root growth, appropriate aeration volume was0.075vvm. Then we studied the biomass and medium dynamics changes of adventitious roots culture, the results showed that fresh weight and dry weight of adventitious roots began to slowly increase from Initial culture to the15th day, then had a sharply increase during15～35days, from31.1g fresh weight (dry weight3.14g) of15d to228.9g (dry weight22.9g), biomass increased slowly during35～40days, almost no further increase after the40th day. The results of determination of the adventitious root oxygen uptake showed that the specific oxygen uptake rate (SOUR) of adventitious roots reached to the highest value in culture for10-15days, after that had a downward trend, but SOUR was no longer declining after35days. There was a linear relationship between EC and dry weight, EC level decreased with the increase of dry weight.We determined the total phenol and polysaccharide content of roots and stems of O.elatus adventitious roots of culturing40d in bioreactor, biennial cultivated and five-year-old, the results showed that the total phenol content of adventitious roots was significantly higher than that of the cultivated roots and stems, the total phenol production reached490.0mg·g-1, While the polysaccharide content of adventitious roots was lower than five-year-old roots and stems, but closed to biennial cultivated O. elatus. The result of antioxidant activity measured using phenol and polysaccharide extract showed that the DPPH radical scaveng rate of adventitious roots was obviously higher than that of biennial cultivated and five-year-old roots and stems, DPPH radical scaveng rate of phenols and polysaccharides extract reached the highest value, it was94%and88%respectively.