Study On The Optimization Of Fermentation Technology For Natamycin

As the secondary metabolites fermented by Streptomyces,natamycin is a kind of polyene macrolide antifungal antibiotic in food and feed industry.Due to its avirulent effect on food preservatives,natamycin is concerned by many studies and will be used widely increasingly.Thus,how to increase the production capacity of natamycin fermented by the current strains in the industrial scale,become important increasingly and shows a strong strategic significance.In this present paper,the strains and fermentation technology of natamycin production were studied and the main conclusions are asfol lows:The optimum temperature of strains used in the present study was 30?under which the strains can grow full and titer units were stable after 9 days cultivation.The optimal formula of culture medium were:dextrin 30.0 g,starch 2.0 g,glucose3.0 g,peptone 5 g,Low temperature soybean meal 3.0 g,K₂HPO₄.3H₂O 0.2 g,CaCO₃ 1.0gand water 1 L.The pH of the culture medium was 7.0.The optimal culture conditions of shake flask were:40 mL of 250 mL bottle and the speed with 220 r/min.The optimal formula of culture medium used in shaking flask fermentation were:glucose 0.5g,dextrin 20.0g,starch 40.0g,industrial peptone 7.5g,Low temperature soybean meal 18g,NH₄NO₃ 2.5g,K₂HPO₄ 0.5g,MgSO₄.7 H₂O 0.5g,KC1 0.3g,CaCO₃3.0 gand water 1 L.The pH of the culture medium was 7.0.The optimal conditions of shaking flask fermentation were:150 mL fermented Liquid of 1000 mL bottled,220 r/min of speed,is 5%of inoculation quantity and 8 days of fermentation period.The optimal initial pH was 7.0 and 1‰of defoamingagent was used in the current study.The optimum fermentation conditions in 30 L fermentor for scale-up were:18 L of Loading volume after inoculation,7.0 of pH value adjusted by NaOH before disinfection?the sterilisaztion condition was on 121?for 30 min?,30?of fermentation temperature,0.05 Mpa of tank pressure,6.5 of the entire pH,400 r/min of stirring speed and 1:0.8?V/V?of ventilation.During fermentation,the microscope morphology,the residual sugar,ammonia nitrogen and dissolved oxygen were detected.The optimal pH was 6.5 in 30 L of fermentor.The verification study showed that the titer were maintained at 6512?g/mL approximately,which increased by 62.8%compared with the initial strains.