Study On Daptomycin Fermentation Technology

Daptomycin is a new generation of Cyclo-lipopeptide antibiotic following vancomycin.Recently,with the rapid development of the domestic daptomycin market,interests in its production aroused.In November 2015,Hangzhou Huadong Medicine Co.Ltd.became the first domestic pharmaceutical enterprise to get the CFDA registered approval.However,the industrial daptomycin production in Huadong Medicine Co.Ltd suffers the drawbacks of low fermentation level,low yield and high cost.The primary goal of this study is to improve the fermentation level and then reduce the production cost.The main works of this paper are as following:Firstly,we optimized the shake flask daptomycin fermentation technology with Sterptomyces roseosporus SY09.The result is demonstrated that the optimum inoculum age,inoculum size,initial pH of medium and medium loading were 28 h,12%?v/v?,pH 8.0 an 30mL/250mL,respectively.Under above conditions,the daptomycin yield reached 296mg/L at 30?and 200rpm in 144 h.The medium components were further optimized.The optimum medium components were as following?w/v?:glucose 2.0%,molasses 2.0%,corn starch 3%,peptone 2%,urea 0.6%,?NH₄?₂Fe?SO₄?₂·6H₂O 0.08%,the initial pH of which is 8.0.With the optimized components and initial pH of 8.0,the maximum daptomycin yield reached 296 mg/l.Secondly,the fermentation process optimization was performed in one 1m³fermenter.The data indicated that the optimum inoculum size,pH and dissolved oxygen were 6%,7.1 and above 30%,respectively.The optimum medium components were as following?w/v?:glucose 2.5%,molasses 2.0%,corn starch3%,peptone 1.5%,urea 0.6%,?NH₄?₂Fe?SO₄?₂·6H₂O 0.08%,the initial pH of which is 8.0.Moreover,an efficient glucose fed-batch fermentation process was established.After 180 h with supplementing 20 g/100 ml glucose,the daptomycin yield reached 2388 mg/L.Finally,the effect of precursor feeding on daptomycin production was investigated in a 15m³ fermenter.The optimum precursor was the mixture of decanoic acid and methyl oleate?1:1,v/v?.The precursor feeding process was further optimized.Under the optimum fed-batch conditions,the daptomycin yield reached 3182mg/l.