Optimization Of Technology For Purification Of Antibiotics From The Fermentation Broth Of Micromonospora Carbonacea JXNU-1

Micromonospora carbonacea JXNU-1 is a rare strain of actinomycetes with broad-spectrum antibacterial activity, which was isolated from soil. Previous research has established the purification process of antibiotics from the fermentation broth of M. carbonacea JXNU-1. On the basis of optimizated the fermentation process, the optimization of technology for purification of the antibiotics produced by M. carbonacea JXNU-1 was explored as followed: The separation process was done by 717 anion exchange resin. The desalting process was through nanofiltration. The purification of the antibiotics was prepared by HPLC. The main results were as follows:(1) The dynamic adsorption conditions on 717 anion exchange resin were optimized by the single factor method. The results showed that the optimum adsorption conditions were as follows: water volume of 2 BV, water flow rate of 2 mL/min, antibiotics concentration of 0.1 mg/mL, pH 5.0, adsorption velocity 1.5 mL/min, and sample volume 3.5 BV. The average adsorption yield of antibiotics was found to be 2500 U/g under the optimum conditions.(2) The elution conditions on the ion exchange were investigated by the single factor and the response surface method. It was seen that the optimum elution conditions were as follows: ethanol concentration of 30%, sodium chloride concentration of 2.5 mol/L, elution volume of 4 BV and elution velocity of 0.5 ml/min. The average extraction yield of antibiotics was found to be 82.3% under the optimum conditions. Response surface methodology with a Box–Behnken design(BBD) was employed to optimize the process for extracting the antibiotics from the broth of M. carbonacea JXNU-1. The effects of three main factors, including the concentration of sodium chloride, concentration of ethanol and elution velocity, on the extraction were investigated and the optimal condition was evaluated by means of response surface methodology. The results showed that the optimum extraction conditions were as follows: ethanol concentration of 40%, sodium chloride concentration of 2.5 mol/L,and elution velocity of 1.1 ml/min. The average recovery yield of antibiotics under the optimum conditions was found to be 86.22%, which was agreed with the predicted value.(3) The salt in the elution solution was removed through the dialysis, the ion exchange, the recrystallization or the nanofiltration methods. It was shown that the concentration of salt in the elution solution was ranged from 6 mol/L to 0.1 mol/L through the nanofiltration method.(4) The crude antibiotics from M. carbonacea JXNU-1 was by high performance liquid chromatography method. Four main chromatographic peaks were obtained under the optimal conditions. The liquid with biological activity was collected when retention time was 2.396 min. The crude antibiotics was prepared through the freeze vacuum drying process.The process of isolation and purification of the antibiotics produced by M. carbonacea JXNU-1 was optimizated. The results would provide the experimental basis for the development and utilization of the antibiotics from M. carbonacea JXNU-1.