Studies On The Process Of Fermentation With Uncooked And Solvent Extraction Of The Ag-antibiotic 702

Streptomyces 702 was screened from soil by Applied Microbiology Laboratory of Jiangxi Agricultural University. The antifungal compound produced by Streptomyces 702 had strongly inhibition on plant pathogenic fungi.it was hopeful to be exploited as a newful and high-performoance biologic bactericide. There is very important to optimizing the fermentation technology to enhancing the yield of antifungal compound.The Streptomyces702-M-N-52 was used as the test strain to study in this paper.Used the modern fermentation optimization technology to optimize the uncooked material fermentation technology of Streptomyces702-M-N-52.Here are the main research methods and results:1. To explore the best technology on producing spores for the Ag-antibiotic 702 strain of Streptomyces 702.Single factor,orthogonal experimental,secondary rotating orthogonal experiment design and pseudo level method orthogonal experiment optimization the Solid Slant and liquid seed cultivation condition.The best medium we obtained was PDA medium for strain of producing the Ag-antibiotic 702.Sucrose concentration was 3%.Peptone and sodium chloride has an inhibitory effect on its.The best combination of culture conditions:culture temperature 29℃,initial pH value 8,incubation time 5 days,In the best medium and cultivating conditions,each tube cant produce spores quantity achieved 4.37 billion,which increased 4.90 times more than those on Gause’s No.1 synthetic medium;The liquid medium was:sucrose 6.67g/L,cornmeal 33.33 g/L,peptone 1.33 g/L,soybean power 20 g/L,CaCO3 0.6 g/L soybean oil 0.4 g/L;the optimum seed culture conditions were as follows:the initial pH8.0,40mL liquid seed culture medium/250mL flask,the spore (T660nm=80%) inoculation rate was 2.5%,30℃,culturered 48 hours on the 200r/min flask shaker. Under the optimum seed fermentation technology,the biomass of the seed increased 70.2% than the original technology,and the yield of antifungal bioactive substance produced by Streptomyces 702 increased 11.7% than the original.2. Under wave bottle conditions,by single factor、secondary rotating orthogonal、four factors three levels orthogonal experiment designs、fed-batch cuitivation according the analysis of parameters of Streptomyces702 shaking-flask fermentations,explore the new process of fermentation with culture undertake autoclave condition by the Streptomyces 702.The optimum medium consisted of (g/L):corn starch 25,corn meal 35, glucose 10,soybean meal 12,peptone 8,KNO3 1,KH2PO4 0.3,CaCl2 5.0,bean oil 5mL/L.The optimum cultural condition were:50mL liquid fermentation medium per 250mL flask,the seed inoculation volume was 10%,uncook fermentationliquid 5%.the initial pH7.0.30℃.200r/min turnover swing bed culture 104hours.Under the optimum medium the antifungal compound production was increased to 7432.6μg/mL by 9.07%.In 48h add 10g/L of glucose and 3g/L of specially,fermented in titer 9548.58μg/mL,than not fill material fermented titer 6021.4μg/mL improve 58.6%atll4h.3.Through the amplification experiment in 500L fermentation tank for fed-batch cuitivation,then determine the metabolic parameters of fermented titer,reducing sugar,total sugar.amino nitrogen,phosphorus and so on by fermentation every 8hours,then establish the partial fermentation and filling materials fermentation metabolic curve,and use Origin 7.5 oftware analysis the experimental data of partial fermentation.compare with shaking—flask,The titer of Ag-antibiotic 702 been increased by partial and fill material circumstances in 500L fermentation tank.rearch 8412.1μg/mL and 12164.8μg/mL respectively,Fill material have increased 74% than none about the productive.4. Choose the best extraction solvent.and research the effect of digestion conditions:proportions by single factor experiment:The study shows that anhydrous methanol was the best infusion for The Ag-antibiotic 702,The best extraction times was the extraction solvent two times than fermentation as volum,soak mention three times can complete 100% extraction rate,the PH of fermentation don’t need adjustment,the temperature and time have little effect.This study have exploration the Extraction Process of Ag-antibiotic 702 preliminary.and laid a foundation for the preparation of Ag-antibiotic 702 microbicides.