Bioprocess Engineering, Wageningen University and Research, Wageningen, Netherlands.
Bioprocess Engineering, Wageningen University and Research, Wageningen, Netherlands.
Metab Eng. 2017 Nov;44:134-142. doi: 10.1016/j.ymben.2017.10.005. Epub 2017 Oct 7.
Direct and selective terminal oxidation of medium-chain n-alkanes is a major challenge in chemistry. Efforts to achieve this have so far resulted in low specificity and overoxidized products. Biocatalytic oxidation of medium-chain n-alkanes - with for example the alkane monooxygenase AlkB from P. putida GPo1- on the other hand is highly selective. However, it also results in overoxidation. Moreover, diterminal oxidation of medium-chain n-alkanes is inefficient. Hence, α,ω-bifunctional monomers are mostly produced from olefins using energy intensive, multi-step processes. By combining biocatalytic oxidation with esterification we drastically increased diterminal oxidation upto 92mol% and reduced overoxidation to 3% for n-hexane. This methodology allowed us to convert medium-chain n-alkanes into α,ω-diacetoxyalkanes and esterified α,ω-dicarboxylic acids. We achieved this in a one-pot reaction with resting-cell suspensions of genetically engineered Escherichia coli. The combination of terminal oxidation and esterification constitutes a versatile toolbox to produce α,ω-bifunctional monomers from n-alkanes.
直接和选择性的中链烷烃末端氧化是化学领域的一个主要挑战。迄今为止,实现这一目标的努力导致特异性低和过度氧化产物。另一方面,中链烷烃的生物催化氧化 - 例如来自 P. putida GPo1 的烷烃单加氧酶 AlkB - 具有高度的选择性。然而,它也会导致过度氧化。此外,中链烷烃的双末端氧化效率不高。因此,α,ω-双官能单体主要使用能源密集型、多步工艺从烯烃生产。通过将生物催化氧化与酯化相结合,我们将正己烷的双末端氧化率提高到 92mol%,并将过度氧化降低到 3%。这种方法允许我们将中链烷烃转化为α,ω-二乙酰氧基烷烃和酯化的α,ω-二羧酸。我们使用基因工程大肠杆菌的休眠细胞悬浮液在一锅反应中实现了这一点。末端氧化和酯化的结合构成了一种从烷烃生产α,ω-双官能单体的多功能工具包。