Effects Of Surfactants And Oxygen-vectors On Diosgenin Production By Dioscorea Zingiberensis Endophtic Bacillus Licheniformis SYt1

Diosgenin,whose chemical name is 5 different spiral sterene-3-beta-alcohol,belongs to different spiral sterene alkyl derivatives.Diosgenin,which can synthesize thousands of kinds of steroid hormone drugs,called "medicinal gold",has become a research hotspot in the world as its significantly high medicinal value and economic benefits.While the action of extracting diosgenin from Dioscorea genus destroys the plant resources and the environment,also restricts the development of relevant industries.In recent years,several purified endophytic strains which can produce diosgenin has been separated and purified from Dioscorea zingiberensis C.H.Wrigh,of which SYt1 has an optimal production of diosgenin and a diosgenin extraction method from the fermentation broth was established.In this study,we mainly focus on the effects of surfactants and oxygen-vectors on diosgenin production by dioscorea zingiberensis endophtic Bacillus Licheniformis SYt1.The test chooses different factors of surfactants and oxygen-vectors firstly.According to the results of single factor tests,we choose the experimental which effect is more ideal for orthogonal test design.According to the result and analysis of orthogonal experiment design,we get the best added dose of various factors to improve the diosgenin production and the verification of SYt1 bacteria high density cultivation by comparison and analysis and the increase of diosgenin production provide experimental basis and reasonable advice for the industrialization of microbial fermentation to produce diosgenin.(1)Single factor analysis of oxygen-vectorsAdded n-hexane,Oleic acid,Ethyl acetate,Soybean oil as oxygen-vectors in the initial stage of fermentation,respectively select ideal concentration of various factors to add time to determine.Except Ethyl acetate have obvious inhibition on bacteria growth,ultimately determine the optimal adding concentration of n-hexane,Oleic acid,Soybean oil were 0.5%,2%,2%,the best time to add is the first day of fermentation period.(2)Single factor analysis of surfactantsAdded Dimethyl Sulfoxide(DMSO),Cetyltrimethyl Ammonium Bromide(CTAB),Sodium Dodecyl Sulfate(SDS),Polyethylene Glycol 6000,Tween-80 as surfactants in the initial stage of fermentation,respectively select ideal concentration of various factors to determine the add time.Finalized the optimal adding concentrations of DMSO,CTAB,SDS and Polyethylene Glycol 6000 were 0.05 g/L,0.1 g/L,0.1 g/L,0.2 g/L,the best time to add is the third day of the fermentation period;the optimal adding concentration of Tween-80 is 10 mg/L in the first day of the fermentation period.(3)Orthogonal DesignAccording to the single factors experiment results and analysis of oxygen-vectors and surfactants,SDS and Tween-80 were selected with n-hexane and Soybean oil to orthogonal design using SPSS.With the result analysis,It is received a test combination for biomass:tween-80 10 mg/L,n-hexane,0.8%,Soybean oil 2%,SDS 0.1 g/L and a test combination for product:tween-80 10 mg/L,n-hexane 0.5%,Soybean oil 2%,SDS 0.06 g/L.Validated and analyzed the results,it will provide a basis study for diosgenin production by Dioscorea zingiberensis endophtic Bacillus Licheniformis SYt1.