知识与财富的链接
综合应用基因组改组和DNA重组技术改进了核黄素生产菌B.subtilis 24/pMX45的性状,在B.subtilis染色体上整合和扩增了多个B.subtilis 24的核黄素操纵子拷贝,并经过两轮的基因组改组后筛得菌株B.subtilis RH33/pMX45,在以12%葡萄糖为碳源的分批发酵中,其核黄素产量约为B.subtilis 24/pMX45的2倍,并具有快速同化利用葡萄糖、生长迅速、可形成感受态和进行基因整合、扩增等优良性状.随后比较分析了三株产核黄素B.subtilis在间歇培养条件下的代谢通量分布,通量分析和实验结果表明,B.subtilis RH33/pMX45中核黄素合成的主要通量限制因素存在于从5-磷酸核酮糖到GTP的一系列反应中.
Traits of riboflavin-producing B.subtilis 24/pMX45 were improved by genome shuffling and DNA recombination.Riboflavin operon of B.subtilis 24 was integrated within chromosome of B.subtilis and was amplified to multi-copies,and B.subtilis RH33/pMX45 were obtained after two rounds of genome shuffling.The strain produced about 100% more riboflavin than the original strain B.subtilis 24/pMX45 in batch culture with 12% glucose as carbon source.In addition, the strain showed some promising traits such as quick assimilation of glucose, rapid growth, competence development and capablity of gene integration and amplification.Subsequently, the metabolic flux distribution in batch culture of three riboflavin-producing B.subtilis were compared and analyzed.The results of flux analysis and experiment indicate that the primary limiting factor for improvement of riboflavin production in B.subtilis RH33/pMX45 lies in the reactions between 5-P-ribulose and GTP.
