【摘要】 透明颤菌血红蛋白(VHb)是一种氧调节、氧结合蛋白,其基因vgb的表达在转录水平上受氧调控.大肠杆菌E.coliBV是采用基因同源重组方法将vgb基因整合到基因工程常用宿主菌E.coliBL21中构建得到的.研究了不同价态的铁离子对同源重组菌的生长特性及VHb合成的影响,研究表明,0.2mmol/L的二价铁离子具有促进VHb表达从而刺激菌体细胞生长的作用.在0.1L/h低通气量条件下,E.coliBV分别进行间歇培养和流加培养,低溶氧刺激VHb在短时间内迅速大量合成,改善了细胞内氧的传递性能,使生长期分别延长到25h和45h,生物量(DCW)分别达到9.6g/L和26g/L.更多还原

【Abstract】 Vitreoscilla hemoglobin (VHb) is a reversible oxygenbinding protein, whose expression is regulated by oxygen at the level of transcription. The growth character of E.coli BV, a vgb gene integrated strain derived from E.coli BL21, was evaluated in shake flask and benchtop scales. The results showed that the addition of 0.2 mmol/L Fe2+ to the culture could improve the growth of E.coli BV significantly, but that the Fe3+ addition did not have such effect. The expressed VHb improved the growth of the host strain under lowdissolvedoxygen conditions and enhanced the protein production. When the airflow rate was only 0.1 L/h, the E.coli BV strain could keep growth for 25 hours and 45 hours respectively, during the batch and fedbatch culture. The biomass (DCW) reached 9.6 g/L and 26 g/L, respectively. It revealed that the strain of E.coli BV grows well in lowdissolvedoxygen conditions.更多还原