摘要
目的:筛选出稳定的高产丁二酮突变菌株,并对其进行发酵动力学分析。方法:以原养型产气肠杆菌(Enterobacter aero-genes编号CICC 10293)为出发菌株,采用紫外线诱变,并结合亮氨酸平板和丁二酮平板筛选方法,获得耐高浓度底物——葡萄糖的高产丁二酮突变菌株,定名为UV-3,利用气相色谱测定代谢产物量,考察诱变前后菌株代谢途径中碳源的流向。基于Logistic和Luedeking-Piret方程,建立突变株UV-3细胞生长动力学、底物消耗动力学、丁二酮生成动力学模型,确定动力学方程。结果:突变株UV-3的丁二酮产量提高18.7倍,达到1.045g.L-1,乙偶姻产量降低48.4%,乙醇产量降低71.4%,乙酸产量提高34.6%,且遗传性质稳定。用实验数据对各种动力学模型进行了验证,拟合度均为98.5%以上。结论:紫外线是一种操作方便,效果良好的诱变方式。绘制了突变株UV-3的发酵曲线,建立了动力学模型,为优化丁二酮的生产工艺奠定一定的理论基础。
To screen a stable, high diaeetyl- producing strain and analyse its fermentation kinetics. Methods： A mutant, designated as UV- 3, was selected from wild- type Enterobacter aergenes 10293 by application of UV irradiation in combination with cultivation in leucine medium and diaetyl medium. Based on the Logistic equation and Luedeking- Piret equation, three kinetic models were proposed for cell growth, product formation and substrate consumption. Results： Gas chromatography was employed to quantified the output of metabolization, and it was found that the yield of diacetyl for the mutant UV - 3 was increased more 18.7 times than that of the wild - type 10293, up to 1.045g. L^- 1. Acetoin and ethanol yields were decreased by 48.4% and 71.4%, respectively. The yield of acetate was increased by 34.6%. With the data from experiment to evaluate model parameters, the three kinetic models appeared to provide a reasonable description for the fermentation process. Conclusion： The method of UV irradiation for selecting high diacetyl- producing mutants was confirmed to be a good method. Curves of fermention kinetics were described and kinetic models were proposed, which will be helpful for optimizing diacetyl fermentation conditions.
出处
《生物技术》
CAS
CSCD
2007年第5期59-64,共6页
Biotechnology
关键词
产气肠杆菌
诱变育种
丁二酮
发酵动力学
Enterobacter aerogenes
mutagenize
diacetyl
fermentation kinetics
