土壤杆菌exoR基因缺陷株生长及其热凝胶合成特性

Characterestics of cell growth and curdlan production in exoR gene knockout Agrobacterium sp. ATCC 31749

为考察exoR基因对土壤杆菌ATCC 31749生长和热凝胶合成的影响,采用三亲本结合方法将含有exoR基因两端同源序列的自杀质粒p JQ-exoR-kan导入土壤杆菌野生菌中,获得了exoR基因缺失突变株。摇瓶发酵验证实验表明,ΔexoR突变株的生长受到一定程度的抑制,exoR的缺失导致了胞外多糖热凝胶的合成量和底物转化率明显增加,分别提高16.8%和19%。研究结果表明,exoR基因参与并强化土壤杆菌合成胞外多糖热凝胶的过程,有助于进一步完善土壤杆菌合成热凝胶的代谢调控网络。

To investigate the effect of exoR gene on the cell growth and curdlan production of A. grobacterium sp.ATCC 31749,a suicide plasmid p JQ-exoR-kan containing two homologous sequences of exoR gene was constructed and transformed it into wild type strain by triparental conjugation method. An exoR gene knockout strain was obtained. Compared with the wild type strain,the cell growth of mutant strain was inhibited. Meanwhile,the curdlan production level and the substrate conversion rate were increased by 16. 8% and 19%,respectively. The results indicated that exoR was involved and played a positive role in curdlan biosynthesis,which further improved the study of the metabolic pathway and regulatory network of curdlan in Agrobacterium sp. ATCC 31749.