白喉杆菌发酵产毒过程中影响因素的分析

Influencing factors of production of diphtheria toxin during fermentation of Corynebacterium diphtheriae

目的分析白喉杆菌发酵产毒过程中,通气方式、通气量大小、培养基成分等影响因素对其产毒的影响。方法采用相对固定的通气和搅拌转速,对比发酵罐底部通气和顶部通气的产毒量;采用顶部通气、相对固定的通气量和搅拌速度,对比胰酶牛肉消化液培养基和酸水解酪蛋白培养基对产毒的影响;采用顶部通气、相对固定的通气量和搅拌转速,使用胰酶牛肉消化液培养基,对比添加L-胱氨酸、麦芽糖、谷氨酸铵对产毒的影响。结果采用顶部通气配合高速搅拌有利于产毒;胰酶牛肉消化液培养基产毒量和产毒速度均优于酸水解酪蛋白培养基;补充碳源和氮源有助于维持白喉杆菌产毒速度和产毒量。结论用胰酶牛肉消化液培养基培养白喉杆菌,配合补充适量的营养成分及提高搅拌速度、增加通气量,对产毒速度和产毒量有促进作用。

Objective To analyze the effect of ventilation mode,throughput of ventilation and component of culture medium on production of diphtheria toxin during fermentation of Corynebacterium diphtheriae.Methods Based on the relatively fixed ventilation throughput and stirring speed,the toxin production under different ventilation modes at the bottom and top of the fermenter were compared.Based on the top ventilation,relatively fixed ventilation throughput and stirring speed,the effects of trypsin-digested beef and acid hydrolyzed casein media toxin production were compared.Based on the top ventilation,trypsin-digested beef medium as well as relatively fixed ventilation throughput and stirring speed,the effects of addition of L-cystine,maltose and ammonium glutamate on production of diphtheria toxin were compared.Results Top ventilation and high-speed stirring were beneficial to the production of toxin.Both the yield and production rate of toxin by using trypsin-digested beef medium were superior to those by using acid-hydrolyzed casein medium.Addition of carbon source and nitrogen source were helpful to maintaining the production rate and yield of diphtheria toxin.Conclusion Culture of C.diphtheriae in trypsin-digested beef medium supplemented with appropriate nutrient components,high-speed stirring and increase of throughput of ventilation promoted the production of diphtheria toxin in both rate and yield.