一株在有氧条件下转化丙酮醇为1,2-丙二醇的大肠杆菌菌株的研究

Research on an Escherichia coli Strain Capable of Transferring Acetol to 1,2-Propanediol Aerobically

本实验室在前期构建了一株能高效利用甘油合成丙酮醇的大肠杆菌工程菌株,如果能在有氧条件下将丙酮醇转化为1,2-丙二醇,则可以大幅提高1,2-丙二醇的合成速率。以大肠杆菌BW25113Δglp K为出发菌株,筛选得到一株可以在有氧条件下代谢甘油的突变菌株PDO1。结果表明,该菌株可以在有氧条件下将丙酮醇转化为1,2-丙二醇,1,2-丙二醇的产量达到0.73 g/L,转化率达到0.493 g/g丙酮醇。突变株PDO1的甘油脱氢酶酶活和胞内的NADH百分比分别是对照株的75.9倍和1.64倍,由此推测,甘油脱氢酶酶活的提高以及NADH的相对提高,使得突变株可以在有氧条件下通过甘油脱氢酶途径代谢甘油,并转化丙酮醇为1,2-丙酮醇。

We constructed an engineered Escherichia coli strain that can efficiently convert glycerol to acetol in our lab,the productivityof 1,2-Propanediol（1,2-PDO）may increase significantly if the strain can convert acetol to 1,2-PDO under aerobic condition. A mutantstrain named PDO1 was screened from original strain E. coli BW25113Δglp K,which metabolized glycerol aerobically. The further experimentsshowed that the strain PDO1 converted acetol to 1,2-PDO with the yield of 0.73 g/L and conversion rate of 0.493 g/g acetol under aerobiccondition. The activity of glycerol dehydrogenase and the proportion of NADH were 75.6 and 1.64 times higher than that of control respectively.It is inferred that the increase of glycerol dehydrogenase activity and NADH level resulted in the mutant strain PDO1 metabolizing glycerol byglycerol dehydrogenase under aerobic condition and the conversion of acetol to 1,2-PDO.