运动发酵单胞菌积累聚羟基丁酸提高乙醇产量

Polyhydroxybutyrate Synthesis in Recombinant Zymonomas mobilis Affected Ethanol Production

运动发酵单胞菌是一种很有潜力的酒精生产菌。PHB是生物合成的一种聚酯,研究表明,该类物质在微生物体内的积累能够提高宿主菌的抗逆能力。对运动发酵单胞菌进行了如下改造将PHB合成操纵子phbCAB与来源于运动发酵单胞菌的丙酮酸脱羧酶的启动子准确融合,插入广泛宿主载体pBBR1MCS-1中,并利用电转化的方法转入到运动发酵单胞菌中。在重组菌中检测到了PhaA和PhaB的酶活;并首次在运动发酵单胞菌中实现了PHB的积累。摇瓶实验表明,前48h重组菌的乙醇积累量提高了约10%,后续发酵中可能由于葡萄糖耗尽,重组菌与野生菌乙醇积累量差别不大。

Zymonomas mobilis was transformed with a polyhydroxybutyrate synthesis operon phbCAB equipped with a pdc promoter from Z. mobilis. For the first time, PHB was produced in recombinant Z. mobilis. Shake flask studies indicated that accumulation of PHB in Zymomonas mobilis increased approximately 10% ethanol productivity for the first 48h of anaerobic fermentation. After that, the PHB effect was observed as insignificant probably due to the exhaustion of the sugar.