Optimization Of Culture Medium And Culture Conditions Of Bacillus Amyloliquefaciens Y14 And Paenibacillus Illinoisensis YZ29

The application of chemical fertilizers and chemical pesticides can cause problems such as soil compaction and potential food safety problems.PGPR is a major source for the development of novel microbial fertilizer strains.Two strains of PGPR strain Bacillus amyloliquefaciens Y14 and Paenibacillus illinoisensis YZ29 were screened out in peanut rhizosphere.Y14 has strong siderophores producing,has good inhibition effect on many kinds of pathogens,and can promote the growth of peanuts.YZ29 can produce siderophores to increase peanut root activity and peanut yield.The spore production of Y14 was found to be low in the production process,and the YZ29 biomass was difficult to increase.The contents of this experiment were performed in order to increase Y14 spore content and YZ29biomass.After the siderophores function test,both strains had better siderophores producing capacity.The Y14 siderophores fermentation broth was crudely extracted,and Arabidopsis thaliana grown on MS-limited iron medium under iron limiting conditions was used.The role of the crude fermentation broth liquid,diluted 10 times,100 times,1000 times,and 10000times the fermentation broth and Arabidopsis thaliana,the plate coated with the fermentation broth is better than the plated Arabidopsis without coating broth growth The leaves were green.When the concentration of the fermentation broth was diluted by 1000 times,Arabidopsis had the best growth status.The number of lateral roots was as high as 18,which was significantly higher than the ck of 7.33 and the leaf area was larger.The Y14 was optimized for the purpose of increasing the production of siderophores and spore production.The SA-limited iron medium was used as the basic medium.The single factor test was conducted first.The final medium formula was:soluble starch,proline,and carbonic acid.Calcium,dipotassium hydrogen phosphate,magnesium sulfate.Using the single-factor obtained materials,five factors and four levels of orthogonal test were conducted.The orthogonal test table was designed for spore production and siderophores production.The proportion of each substance was determined by orthogonal test to improve spore production:soluble starch.80g/L,proline 7.5g/L,magnesium sulfate 2g/L,dipotassium phosphate0.25g/L,calcium carbonate 1g/L,optimized spore yield can reach 2.235×10~5cfu/mL;to increase siderophores production The proportion of each substance was determined by orthogonal test:soluble starch 30 g/L,proline 7.5 g/L,magnesium sulfate 2 g/L,dipotassium phosphate 0.3 g/L,calcium carbonate 1.5 g/L,siderophore activity The unit reached 49.96.