Strains Breeding And Grooming Conditions' Optimization Of The Doramectin Bacteria

Dora bacteria is a new macrolide compounds, which is produced a high-performance, low toxicity, broad-spectrum antibiotics insecticidal by fermentation. They are the most effective agricultural pesticides and antiparasitic agents, and widely used in veterinary and agricultural fields.In this paper, the strain ATCC37 occurs a series of physical and chemical mutagenesis and the application of genome shuffling,obtaining the high-yielding strains of the doramectin ATCC37.A stable and high-yielding strain ATCC37-6(titer is 30ug/ml) was obtained from Primitive strain by stable experimentation. Obtains strain N159 (high-yielding strain,titer is 30ug/ml) and ATCC37-12 (good growing and low-yielding) after a series of mutagenesis, and celebrates magnamycin resistant plate screening through the sulfuric acid chain mildew element, obtains strain S159 and strain G159.As the parent carries on the genome team take S159, G159, ATCC37-12 and ATCC37 to rearrange the breeding research. After five round recursive fusion, the strain F5-78 was obtained, which can produce 105.3μg/mL. It was increased 28.4% more than the original strain N159.Subculture experiment indicated that the F5-41 was genetically stable.Optimization of fermentation conditions in the high-yield research,carried out on culture medium optimization simple carbon source is corn starch,nitrogen sources for the soybean meal and yeast.Doramectin produced by the fermentation characteristics influence of temperature,liquid capacity,transplanting quantity and age of the aspects of doramectin fermentation,the results show that:the strains of the optimal fermentation temperature of 28℃,seed age 42h,20% of precursors cyclohexyl acid as 250ul/30ml,bottled volume 30ml,the number of days the fermentation production of doramectin 11 days maximum.