An evolved Escherichia coli strain for producing hydrogen and ethanol from glycerol
An evolved Escherichia coli strain for producing hydrogen and ethanol from glycerol
复制标题
DOI：
10.1016/j.bbrc.2009.12.013
复制
发表时间：
2010-01-01
影响因子：
3.1
通讯作者：
Wood, Thomas K.
中科院分区：
文献类型：
--
作者：
Hu, Hongbo;Wood, Thomas K.
甘油是一种很有吸引力的生物燃料原料，因为它在生物柴油操作过程中作为副产品积累：因此，在这里，我们考虑使用大肠杆菌的甲酸盐氢裂解酶系统将甘油转化为氢，该酶系统将丙酮酸转化为氢，从缺乏富马酸还原酶的大肠杆菌BW25113frdC开始(该突变减少了甘油发酵过程中氢合成的抑制)，并通过使用适应性进化和化学诱变结合基于油增加生长油甘油的选择方法，获得了一株改良菌株HW2。在甘油(0.6 8+/-0.16 mm ol/L/h)中产氢比BW2 5 113frdC快5倍(0.2 5+/-0.0 1/h)，达到了合理的厌氧生长速率。与3W25113frdC相比，HW2中的甘油脱氢酶活性增加了4倍，证实了产氢量的增加。此外，全转录组研究表明，在HW2中，几条降低氢产率的途径(FDP、FOCA和gatYZ)受到抑制，而EN(ODES烯醇化酶)则被诱导。进化的HW2菌株(C)2009 Elseviei Inc.的乙醇产量也增加了5倍。保留所有权利
Glycerol is an attractive feedstock for biofuels since it accumulates as a by product during biodiesel operations: hence, here we consider converting glycerol to hydrogen using the formate hydrogen lyase system of Escherichia coli which converts pyruvate to hydrogen Starting with E coli BW25113 frdC that lacks fumarate reductase (this mutation reduces repression of hydrogen synthesis during glycerol fermentation) and by using both adaptive evolution and chemical mutagenesis combined with a selection method based oil increased growth oil glycerol, we obtained an improved strain, HW2. that produces 20-fold more hydrogen in glycerol medium (0 68 +/- 0 16 mmol/L/h) HW2 also grows 5-fold faster (0 25 +/- 0 01/h) than BW25113 frdC on glycerol, so it achieves a reasonable anaerobic growth rate. Corroborating the increase in hydrogen production, glycerol dehydrogenase activity in HW2 increased 4-fold compared to 3W25113 frdC In addition, a whole-transcriptome study revealed that several pathways that would decrease hydrogen yields were repressed in HW2 (fdp, focA, and gatYZ) while a beneficial pathway which en(odes enolase was induced. Ethanol production was also increased 5-fold in the evolved HW2 strain (C) 2009 Elseviei Inc. All rights reserved