Enzyme and reaction engineering of unspecific peroxygenase driven hydroxylation of butane (BUPOx)

Holtmann教授和Liese教授的联合提案旨在深入了解工艺参数对短链烷烃氧官能化生物催化效率的影响和相互作用。以新出现的酶群催化丁烷不对称羟基化制2-丁醇为例，对非特异性过氧化物酶（UPO）进行了详细的跨学科过程研究。两组在第一次泡塔实验中进行了共同的初步研究，证明了该反应体系的可行性，同时指出了进行更详细研究以掌握所观察到的拮抗效应的必要性。首先，模型酶AaeUPO将被表征。特别令人感兴趣的是过氧化氢进料速率的稳定性和气态丁烷进料的气体效应。为了提高相关的选择性，新的UPO变体的筛选（对映体选择性）将与反应工程相结合，重点是通过萃取来原位去除产物（过程选择性）。由于upo显示了广泛的底物范围，因此有必要进行“反向”底物筛选，以同时找到合适的非底物溶剂。最后，有希望的UPO变体将固定在集成在反应器中的气体扩散电极上。通过这种方式，在克服upo催化羟基化的限制因素方面产生了新的基础知识。

This joint proposal of the working groups of Prof. Holtmann and Prof. Liese aims at the profound understanding of the influences and interactions of process parameters on the biocatalytic efficiency of the oxy functionalization of short chain alkanes. On the example of the asymmetric hydroxylation of butane to 2-butanol catalyzed by the recently emerging enzyme group, the unspecific peroxidases (UPO) detailed interdisciplinary process studies are carried out. The feasibility of the reaction system was already demonstrated in common preliminary research by the two groups in first bubble column experiments and at the same time the necessity for more detailed investigations to grasp the observed antagonistic effects. At first a model enzyme, the AaeUPO, will be characterized. Of particular interest is the stability regarding hydrogen peroxide feed rate and gassing effects from gaseous butane feed. To improve relevant selectivities a screening for new UPO variants (enantioselectivity) will be combined with reaction engineering, focusing on in situ product removal by extraction (process selectivity). As UPOs display a broad substrate scope, a “reversed” substrate screening is necessary to find suitable solvents that are not substrates at the same time. Lastly, promising UPO variants will be immobilized on a gas diffusion electrode that is integrated in the reactor. By this means new fundamental knowledge is generated in terms of overcoming limiting factors for hydroxylations catalyzed by UPOs.