【作者】 陈冠群；

【导师】 杜连祥；

【作者基本信息】 天津科技大学 ， 发酵工程， 2003， 硕士

【摘要】 本论文首先确定了纳他霉素的检测方法—HPLC法；然后对纳他霉素产生菌发酵性能做了初步研究。对其发酵工艺进行了优化，并根据其合成机制，对其代谢调控进行了初步研究。最后在5L自动罐上研究了纳他霉素的间歇补料分批发酵。 确定了HPLC法检测发酵液中纳他霉素的各项参数：在Phenomenex prodigy 5μ ODS3 100A(250mm×4.60mm i.d.，5μm)色谱柱上，以甲醇-水-磷酸(体积比85:15:0.15)为流动相，流速为1mL/min，紫外检测波长为303nm。 在研究菌株发酵性能的基础上，优化了发酵培养基配方：葡萄糖36g/L，大豆蛋白胨20g/L，酵母粉4.5g/L，pH7.9。 根据纳他霉素的合成途径，研究了前体物及代谢调节物对发酵的影响。结果表明，亚铁氰化钾和生物素都对纳他霉素的合成无促进作用；在初始培养基中加入0.5％的磷酸镁并在快速生长末期加入0.1％的丙酸钠能提高纳他霉素的产量，使之达到2.79g/L。 以模糊理论为基础，以生长生产耦合度定量表征了菌株生长和生产的同步程度。发现在发酵过程中生长和生产不同步，耦合度仅为4.09％。 在5L机械搅拌发酵罐中进行了控制pH间歇流加培养实验。确定的工艺参数为：pH控制为45h前保持6.5，45h后保持5.5；从第45h开始流加50％葡萄糖，以发酵液中葡萄糖水平为控制指标，维持葡萄糖浓度20g/L；培养时间为93h。最终纳他霉素产量达到2.97g/L。更多还原

【Abstract】 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更多还原