Mutation Inducing Breeding Of Avilamycins Production And Optimization Of Fermentation Conditions

The avilamycin, which is produced by Streptomyces viridocbromogene, is oligosaccharide antibiotics and belong to the orthosomycin group of antibiotics. Avilamycin is licensed for use as a gouth promoter.In this research, combined with UV and NTG mutation screening high-yielding resistant strains can be bred for the production of high-yielding strains Avilamycin SDSL-284, titer 843μg/ml, increaseing 106.6% compared with the original strain. Duaring slant culture of the strain, the richness of slant spores is directly related to the medium, the quality of agar is directly related to concentration of spores. Swallow agar favor the accumulation of spores; the fresh slant can only save 2 weeks. ADM produces Bacteria pull of preservation are discussed, frozen spores found the best way to preserve species. Inoculum of cryopreservation spores great affect seed quality in the seed bottle, and the research ultimately determine the frozen spore inoculum of 0.5%, or about 0.2×107 spores.Carbon content of the fermentation medium is studied. The best combination of carbon is determined. That is soluble starch 40.0g / l and glucose 20.0g / l. Under this combination sugar supplement can increase the yield of Avilamycin seed cultivation parameters are explored. That is seed culture temperature is 28℃, the optimum pH range of the medium should be controlled at 6.4 to 6.6; dissolved oxygen level is controlled at 30% to 50%, age of the seed tank is about 30h, amount of transfer seed is 5%. Under such conditions, process parameters and process control of the fermentation tank are optimized. The initial pH after sterilization is 7.0 to 7.2, the process of fermentation control pH around 6.7 using 30% of alkaline, the reducing sugar concentration maintain 5~20g/l supplemented with glucose. Calcium chloride concentration is maintained at 6~8g/l, a one-time additional 0.25% L-valine after 24h, and then every 48h additional 0.1%. In order to improve the ratio of the components.After optimizating the fermentation process, the amplification of 20T is studied. The average titer of 3 batches is 1590μg/ml, the average gross margin is 46.0%, The research achieves a large production capacity.