【摘要】 本文考查了螺旋霉素发酵过程中溶氧的变化规律,不同溶氧水平对螺旋霉素发酵的影响,各种前体、混合碳源、氮源等对溶氧变化和发酵单位的影响。试验结果表明:在使用混合碳源下,溶氧在发酵过程中一般会出现3次低谷;溶氧水平在发酵前期一般维持在10～40%,后期维持在40～70%空气饱和度的水平,溶氧过高或过低均不利于螺旋霉素的生物合成;前体中乙酸钠有提高发酵单位的作用。比较不同比例的混合碳源发现,淀粉∶葡萄糖=5.5～6.5∶1时发酵中后期的呼吸仍较强,其溶氧水平在50～60%,混合碳源中含乳糖或蔗糖时发酵中、后期呼吸减弱,溶氧水平在75%以上。比较不同菌种的生产能力时也发现,中、后期呼吸减弱的,发酵单位低。发酵培养基中加适量油,可降低糖耗1/3,提高发酵单位42%。更多还原

【Abstract】 Dissolved oxygen (DO) is liable to become a control factor during the fer mentation of antibiotic. The effect of DO on spiramycin(SPM)fermentation was investigated, Experimental results showed that with the use of glucose and starch as carbon source, the DO curves usually descend from 100% air saturation to valleys between 10～40% thrice during SPM fermentation. The critical value of DO for SPM biosynthesis is about 10% sat., and the DO level higher than 75% shows an adverse effect on SPM production. Among the precursors tested, sodium acetate enhances the yield of SPM significantly. Adequate amount of peanut oil has an effect of repressing the consumption rate of sugar and consequently improving the fermentation condition by cutting down considerably the amount of starch used, with the result of increasing SPM potency by 40～50%.更多还原