Studies On Fermentaion Process For Producing Natamycin

The determination methods of natamycin-HPLC was studied. Based on the study of strain's fermentation ability, the medium was optimized and the metabolic control of No5 was studied. Finally, fed-batch fermentation was studied to improve the yield of natamycin in 5L auto-fermentor.The parameters of HPLC were determined. The operating conditions were Phenomenex prodigy 5 ?ODS3 100A(250mm?.60mm i.d., 5 ?m), at room temperature, methanol-water-phosphoric acid (85:15:0.15, V/V) as mobile phase with a flow rate of l.0mL/min and UV detection at 303nm.Based on the study of its fermentation ability, the optimum medium for natamycin production was demonstrated (g/L): glucose 36, soybean peptone 20, yeast extract powder 4.5 and pH 7.9.Based on natamycin's synthesis way, the influence of precursor and regulator on natamycin production was explored. The result showed: K4Fe(CN)6-3H2O and biotin have no positive effect on natamycin production. Adding 0.5% magnesium phosphate at the beginning and 0.1% sodium propionate before the end of logarithmic growth phase can improve natamycin production of flask to 2.739g/L.Based on the fuzzy theory, ration of coupling growth and expression was introduced to show the extent of biomass growth and natamycin production in fermentation. It was shown that the growth and production were not synchronous in the original process and the ration of coupling was only 4.09%.The fed-batch fermentation with pH control was determined based on the studies of batch fermentation result in flask. pH was controlled at 6.5 before 45h and 5.5 after that. 50% glucose began to be added by pulsed feeding at 45h, and the glucose concentration was maintained about 20g/L during fermentation process. The fermentation time was 93h. The yield of natamycin under these conditions was 2. 97g/L...