摘要
在合成培养基中分别添加缬氨酸(Val)、异亮氨酸(Ile)与亮氨酸(Leu)考察其对必特螺旋霉素生物合成的影响,证明Val、Ile及Leu对必特螺旋霉素多组分的合成有着不同的调节作用。实验结果表明在36h分别添加0.5g/L的上述三种氨基酸,发酵液pH和铵离子浓度存在着显著差异,而Val脱氢酶活性都增加了2～3倍。添加Val使菌体在60h之前糖耗速率加快,达到1.0g/(L.h),胞内丙酮酸积累,丙酮酸羧化酶活性增加20%～95%,柠檬酸合成酶活性降低41%,发酵液中丙酸和丁酸出现先增加后降低的现象,最终效价比对照高出45.3%,而总异戊酰组分则降低了23%,其他酰化组分降低了39.6%;添加Ile以后菌体糖耗速率降至对照的30%～40%,柠檬酸合成酶活性降低了47%,发酵液中的乙酸、丙酸、丁酸都出现大量积累的现象。最终效价为对照的85%,而丙酰螺旋霉素III、乙酰螺旋霉素以及异丁酰螺旋霉素组分含量分别增加126%、50%、296%。添加Leu对初级代谢影响不大,异戊酸在胞外积累,随后被重新吸收利用,最终异戊酰基螺旋霉素II和异戊酰基螺旋霉素III组分分别提高了41%和50%。同时总异戊酰基螺旋霉素相对含量也比对照提高了41.9%,效价和对照基本一致。
This paper demonstrated that supplementing valine （L-Val）, isoleucine （L-Ile） and leucine （L-Leu） in synthetic media had different effects on biosynthesis of multi-components of biotechspiramycin. The results showed that the supplement of 0.05g/100ml amino acids after 36h of fermentation resulted in different pH values and ammonium ion concentrations of fermentation broth, and 2 to 3 time-increase of the activity of valine dehydrogenase. Within 60h after the supplement of L-Val, the glucose consumption rate was increased to 0. 1 g/（100ml·h）, pyruvic acid was accumulated inside the cells, the activity of pyruvate carboxylase （PC） was increased in the range of 20%-95%, the activity of citrate synthase （CS） was decreased by 41%, the propionic acid and butyric acid in the fermentation broth were increased at first and then decreased with the ultimate biological titer of biotechspiramycin being 45.3% higher than that of the control group, the relative content of total isovalerylspiramycin components were decreased by 23%, and the relative content of other acylated components was deciined by 39.6%. After the supplement of L-Ile, the giucose consumption rate was decreased to 30%-40% then that of the control group, the activity of CS was decreased by 47%, large amounts of acetic acid, propionic acid and butyric acid in the fermentation broth were accumulated in the cells with the ultimate biological titer of biotechspiramycin being 85% （of that） of the control group, and the relative content of propionylspiramycin Ⅲ, acetylspiramycin and isobutyrylspiramycin component were increased by 126%, 50% and 296% respectively. However, L - Leu had no obvious effect on primary metabolism of biosynthesis of biotechspiramycin. After the supplement of L-Leu, extracellular isovaleric acid was accumulated in vitro and then reabsorbed for eutilization, the ultimate relative content of isovalerylspiramycin Ⅱ, isovalerylspiramycin Ⅲ was increased by 41% and 50% respectively, and the relative content of total isovaleryl-spiramycins increased by 41.9% with the biological titer of biotechspiramycin being equal to that of the control group.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2007年第11期660-668,共9页
Chinese Journal of Antibiotics
基金
上海市科委项目(064319033)
教育部回国留学人员基金
