Selection Of Initial Medium In Fed-Batch Culture Of Rhodiola Sachalinensis Callus Based On AHP-TOPSIS Method

Rhodiola sachalinensis A.Bor.is is a perennial herbaceous medicinal plant with high medicinal value.However,the lack of R.sachalinensis wild resource and the immature artificial cultivation system in the rencent years restricted the development and production of the related medicinal products.As a technology basing on the theory of plant tissue culture,bioreactor culture can obtain a large amount of plant materials in a short time without occupying traditional cultivated land.In this technology,the fed-batch culture operation can effectively avoid the substrate inhibition phenomenon in the initial stage of the culture,and further promote the growth of plant cells and the accumulation of active substances.In the process of establishing a fed-batch culture system,the regulation of the initial medium components is one of the key steps to achieve high-efficiency culture.However,it’s difficult to achieve the maximum value of multiple evaluation indicators at the same level when selecting the medium components.Therefore,it is of great significance to select a reasonable comprehensive evaluation method for the selection of medium components while facing this complicated situation.As a scientific decision analysis method,analytical Hierarchy Process（AHP）-technique for order preference by similarity to ideal solution（TOPSIS）can accurately evaluate programs subjectively and objectively.Above all,in this research,the fed-batch culture of R.sachalinensis callus was studied on the basis of batch culture and the best initial medium components were selected basing on the AHP-TOPSIS.The findings of this study aim to provide a new way for rapidly obtaining a large number of R.sachalinensis plant materials with stable bioactive substance content.In this study,the AHP-TOPSIS method was successfully used to both subjectively and objectively select the best initial medium components in the fed-batch of R.sachalinensis callus.The 5 L bioreactors were used for fed-batch culturing R.sachalinensis callus in this study and the effects of initial medium volume,serval kinds of inorganic salt concentration and sucrose concentration on callus biomass and bioactive substance（salidroside,total polysaccharides,total flavonoids and total phenols）accumulation were explored.The results showed that the fed-batch mode effectively increased the callus biomass and bioactive substance content.When the initial medium volume was 3 L,it was the most beneficial for callus growth and bioactive substance accumulation.Furthermore,when MS medium concentration was halved and the nitrogen concentration was adjusted to 30 m M;NH₄⁺/NH₃^-was adjusted to 5/25 m M;the phosphorus concentration was adjusted to 0.94 m M;the calcium concentration was adjusted to 4.5 m M,the callus biomass and the content of bioactive substance were increased obviously.Finally,the sucrose concentration had a significant impact on fed-batch culture.The 30 g L^-1 of sucrose concentration in initial medium promoted the accumulation of callus biomass and bioactive substance.Under these conditions,the fresh weight and dry weight of callus in a bioreactor（5 L）could be harvested 786.5 g,and 35.5 g respectively and 347.74 mg of salidroside,4718.80 mg of total polysaccharides,25.88 mg of total flavonoids and 96.27 mg of total phenols also could be obtained.The selected initial medium under fed-batch culture in this study provides a theoretical basis for further completing of the fed-batch culture system of R.sachalinensis callus,and is full of great significance to protect R.sachalinensis wild plant resources.