Screening And Fermentation Condition Research Of Two Steroidal Saponins-producing Endophytes From Paris Polyphylla Var. Chinensis Franch

One hundred and seven endophytic bacteria were isolated and purified from the fresh hypogeal stems of Paris polyphylla var Chinensis .The steroid saponins were examined in the fermentation cultures of some bacteria. It was found that two bacteria which named RZ03and RZ07 could produce steroid saponins and have been studied. Based on the result of TLC.This initially think the two endophytic bacteria may produce steroid saponins.It needs further research to insure which steroid saponins it produce and wether it is the active institution.Baced on its morphological characteristics,growth patten and physiological -biochemical characteristic,We initially identify RZ03 is Enterobacteriaceae,RZ07 is Bacillus.And then We use 16S rDNA molecular series analysis to identify these two bacterias. RZ03 and RZ07 which could produce diosgenin were screened by TLC. The morphology, physiological and biochemical characteristics indicated and The sequences of 16S rDNA fragements were analyzed The homologous sequences were obtained by blastn from GenBank+EMBL+DDBJ,and the 16S rDNA phylogenetic tree were constructed by ClustalW. The homology between strainRZ03 and DQ019167(Exiguobacterium acetylicum) is 99%,so RZ03 was identified Exiguobacterium acetylicum RZ03.The homology between strain RZ07 and DQ207730(Bacillus subtilis) is 99%, so RZ07 was identified Bacillus subtilisRZ07 .Have carried out preliminary research for the RZ03's antibiosis activity and the condition fermenting,Result is indicated:(1) The most suitable culture medium composition fermenting is:15% White potato juice,3% Bran juice,2.5% Cane sugar,0.15% MgSO₄·7H₂O,0.3%KH2PO4。(2) The most suitable condition fermenting is: Period fermenting 6-7d,fermentation temperature 35'C,The begaining PH of culture medium fermenting is 5.0-6.0,Hold amounts with culture medium fermenting 100-120ml/500m1triangle bottle,Table concentrator rotation rate 120-160r/min,The most suitable inoculate with amounts is 10%-15% (v/v)。(3) The hot stability admeasurement is indicated: Held active material do not resist heat,but have a few heatproof components。...