The Key Technology Analysis And Optimization Of Nosiheptide Fermentation Process

Nosiheptide was one of polypeptide antibiotic produced by Streptomyces actuosus, combined by unsaturated fatty acid and kinds of amino acid. It mainly contained Nosiheptide A and Nosiheptide B, with a little C and D.It was active to Gram-positive bacteria by inhibiting cell wall peptidoglycan synthesis, especially for staphylococcus aureus and bacillus subtilis. In favour of animal growth, Nosiheptide was widely used in the production of animal husbandly. This paper was to study Nosiheptide manufacturing by the strain Streptomyces actuosus KS 010, established the method to detect the content of Nosiheptide, breeded the high-level producing, optimized fermentation conditions.Firstly, the content of Nosiheptide was detected by the method of Microbiological Assay and HPLC. For Microbiological Assay, the determination conditions were optimized through the investigations of extraction solution composition, extraction time and the concentrations of bacillus subtilis. acidic acetone solution B (acetone:2mol/LHCl: H2O=20:l:21,40 min for extraction. The determination conditions for HPLC were optimized through the investigations of mobile phase composition, mobile phase flow and extraction time.The optimum deternmination conditions were acetonitrile:35 mM KH2PO4 (30:70), flow 1.OmL/min in the detection wavelength of 267 nm.From the one-way analysis, the best liquid fermentation condition was optimized.The optimal seed medium was composed of corn flour 10g/L, glucose lOg/L, corn steep Iiquor15 g/L, peptone 5 g/L, (NH4)2SO45g/L,KNO32.5 g/L, NaCl 2g/L,CaCO34g/L, pH 7.0, tempreture 28℃. Fermentation medium was composed of com flour2.7%, corn steep liquor 2.1%, corn gluten meal 1.3%, NH4CI 0.1%, NaCl 0.5%, CaCO30.2%, yeast cream 1.2%, K2HPO410.3 mmol/L, ZnCl 8.4 mmol/L and glucose 6.3%, tempreture 28℃, after fermentation for 7 days, the titer of Nosiheptide was the highest at 2158.33 U/mL.