Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, California 90095, USA.
J Am Chem Soc. 2011 Aug 3;133(30):11399-401. doi: 10.1021/ja203814d. Epub 2011 Jul 7.
An Escherichia coli strain was engineered to synthesize 1-hexanol from glucose by extending the coenzyme A (CoA)-dependent 1-butanol synthesis reaction sequence catalyzed by exogenous enzymes. The C4-acyl-CoA intermediates were first synthesized via acetyl-CoA acetyltransferase (AtoB), 3-hydroxybutyryl-CoA dehydrogenase (Hbd), crotonase (Crt), and trans-enoyl-CoA reductase (Ter) from various organisms. The butyryl-CoA synthesized was further extended to hexanoyl-CoA via β-ketothiolase (BktB), Hbd, Crt, and Ter. Finally, hexanoyl-CoA was reduced to yield 1-hexanol by aldehyde/alcohol dehydrogenase (AdhE2). Enzyme activities for the C6 intermediates were confirmed by assays using HPLC and GC. 1-Hexanol was secreted to the fermentation medium under anaerobic conditions. Furthermore, co-expressing formate dehydrogenase (Fdh) from Candida boidinii increased the 1-hexanol titer. This demonstration of 1-hexanol production by extending the 1-butanol pathway provides the possibility to produce other medium chain length alcohols using the same strategy.
通过扩展外源酶催化的辅酶 A（CoA）依赖性 1-丁醇合成反应序列，工程大肠杆菌菌株能够从葡萄糖合成 1-己醇。C4-酰基辅酶 A 中间体首先通过来自不同生物体的乙酰辅酶 A 乙酰转移酶（AtoB）、3-羟丁酰辅酶 A 脱氢酶（Hbd）、丁烯酰辅酶 A 酶（Crt）和反式烯酰辅酶 A 还原酶（Ter）合成。合成的丁酰辅酶 A 通过β-酮硫解酶（BktB）、Hbd、Crt 和 Ter 进一步延长至己酰辅酶 A。最后，己酰辅酶 A 通过醛/醇脱氢酶（AdhE2）还原生成 1-己醇。通过使用 HPLC 和 GC 的测定法证实了 C6 中间体的酶活性。在厌氧条件下，1-己醇被分泌到发酵培养基中。此外，共表达来自 Candida boidinii 的甲酸脱氢酶（Fdh）增加了 1-己醇的产量。通过扩展 1-丁醇途径生产 1-己醇的这种证明为使用相同策略生产其他中链长度醇提供了可能性。
