Fermentation Optimization And Mutation Breeding Of The Streptomyces JS-1~T

This research is mainly on optimization for fermentation media and conditions of Streptonyces JS-1T,and meanwhile breeding high yield strains through mutation.Take pathogenic Mcogone perniciosa 0011 as indicator bacteria,and measure JS-1T fermented liquid bacteriostatic diameter as response values.(1)Using the single factor and response surface analysis,to optimize the shake flask fermentation medium of JS-1T.Through the single factor experiment to investigate the carbon source,nitrogen source and all kinds of inorganic salt effection on the antibacterial activity of strains fermented liquid,and through PB design to screen out yeast powder,NaCI,KH2PO4 as the main factors,and all show positive effect.Then then steepest uphill experiment center to fugure out the concentration point,that is yeast powder respectively 1.5%,0.115%NaCl and 0.005%KH2PO4.Finally through center combination experiment result is analyzed to get a regression equation,the equation to calculate the maximum coordinates is the partial derivative of each main factor concentration,eventually the optimized medium is composed of 7.5%glucose,yeast powder 1.7%,NaCl 1.7%,K2HPO4 0.1 ‰ and 0.02%CaCO3,0.02%MgSO4,the fermentation production was increased by 55.5%compared with the basic medium.(2)Using both single factor and orthogonal experiment,to optimize the fermentation conjditions.Firstly,through single factor experiment of shaking flask fermentation is suitable for kinds of age for 96 h,pH6.5-7.5,70 mL/250 mL,fluid volume and quantity of 10%,table speed 180 r/min,temperature 28 and then by the Lg(34)orthogonal design experiment shows that four important factors on the fermentation production of antimicrobial active substances affect the strength of the sequence is:speed>temperature>pH>inoculation quantity,and the best combination of various conditions for pH7.0,rotating speed of 200 r/min,temperature 28?,10%inoculated quantity,verified by the fermentation condition combination Streptomyces fermentation JS-1 t and its fermented liquid bacteriostatic circle average diameter of 3.47 cm,antibacterial activity is increased about 11.58%before optimization.(3)Investigates the physical and chemical properties of fermented liquid,through acid and alkali,heat and ultraviolet irradiation treatment,it is found that the activity of fluid is stable in neutral environment,and keeps good stability under heat and uv-irradiation.(4)Enlarge the fermentation process of JS-1T from shaking flask fermentation 51 fermentation tank to examines metabolic features including the pH of the ferment-ation process,sugar metabolism,antimicrobial activity of biomass,dissolved oxygen,fermented liquid,etc.Investigate the relations between substrate consumption and amount of bacteria,as well as the relations between the activities of fermented liquid.The results showed that the fermentation tank fermentation is more conductive to the accumulation of biomass,Strains of antimicrobial active substances synthetic growth type coupling.(5)Through UV and EMS mutation breeding,we get 3 high-yield strains Al,A2 and A7,the average diameter of shake flask fermentation liquors up to 3.58 cm,3.82 cm and 3.77 cm,meanwhile the antibacterial activity is increased by 82.65%,94.9%and 82.65%respectively compared with the starting strain(1.96 cm).