Study On Synthetic Ability And Pathway Of Beijerinckia Indica BY - 3 Strain

This study is based on the Azotobacter plant root soil around the middle IAA asthe research object, objective in nitrogen fixing strains isolated from IAA in high yield,the results can be applied to the field of agricultural production, can reduce thechemical fertilizer, reduce eutrophication, promote plant growth, protect theecological environment.Isolated13strains of nitrogen fixing bacteria from soil samples collected fromdifferent ecological environment in Shanghai Fengxian District Bay area, purificationand determination of IAA content in the fermented liquid culture after bottle, whichthe BY-3strain of IAA yield reached52.58mg/L. Gram negative bacteria BY-3, BY-3were cultured in Ashby mannitol medium pale creamy yellow, giant colony, colonysurface was smooth, and then into the fold, a surface wrinkles or folds. Bysequencing the16srDNA of length1436bp, identified as Beijerinckia indica.The optimization results show that the single factor experiment, the bacteriaBY-3in shaking speed250r/min, culture temperature30℃, inoculated cell density ofOD6000.40, pH5.0, adding trace molybdenum iron when most appropriate growth,at the same time IAA synthesis yield.Processing method, different extracting agents and different mobile phasesystems by using different samples, optimization of extraction and chromatographicconditions combination, further improve the accuracy of determination method ofIAA content, the HPLC detection method of IAA has the advantages of simpleoperation, high precision, good recovery rate etc.. The chromatographic conditions,chromatographic column is the Agilent ZORBAX Eclipse XDB-C18column(250mm*4.6mm); the mobile phase acetonitrile-2%acetic acid water (volume ratio1:4); the flow rate was1.0ml/min; ultraviolet wavelength is280nm; columntemperature was30℃; the injection volume was10ul; the extracting agent is thechoice of the acetic acid ethyl ester. In the IAA standard sample of IAA peak time was5.803min, the fermentation broth of the strain BY-3of IAA peak time of5.796min.Through the HPLC analysis method in fermented broth of the strain BY-3except IAA, the existence of the indole pyruvic acid, indole acetamide, indole acetaldehyde,ethanol, tryptamine, indole indole acetonitrile as the representative of theintermediate IAA biosynthesis metabolism process, the results indicate the presenceof indole ethanol fermentation broth of the strain BY-3, the strain BY-3IAAbiosynthesis pathway is the indole pyruvate metabolic pathways or tryptophan sidechain of metabolic pathways, or both exist together, because these two approachesare the presence of intermediate product of indole acetaldehyde.