Hydrogen peroxide dependent enzymes (peroxidases and lipases)

Bild Forschungsprojekt

Hydrogen peroxide is a mild and stable oxidant which can be regard as a "green" reactant. While it has been in use for traditional chemical syntheses for some time, recently more and more biocatalytic reactions which utilize hydrogen peroxide as a cosubstrate are being developed. A variety of reactions utilizing hydrogen peroxide can be carried out, i.e. hydroxylations, epoxidations, sulfoxidations, halogenations, Baeyer-Villiger-oxidationens, and decarboxylations. In order to transfer such reactions to industrial scale, DFI combines molecular biological and process engineering to adress the challenges of hydrogen peroxide based biocatalysis.

PeroxyMEER - Increasing the spectrum of Peroxygenase-catalyzed hydroxylations through discovery of new enzymes, novel metagenome screening, enzyme engineering, and reaction engineering

Period:  01.08.2017 - 31.07.2019
Partner: RWTH Aachen, TU Dresden, Universität Hamburg
Funder:  AiF
Project Manager: Sebastian Bormann, Dirk Holtmann
Research Group: Industrielle Biotechnologie 

With the discovery of fungal peroxygenases (unspecific peroxygenases, UPO), a new and promising tool for synthetic chemistry has become available, because these enzymes combine the selectivity of P450-monooxygenases with the requirement for a cheap substrate, hydrogen peroxide.

The goal of the project PeroxyMEER is to increase the diversity of peroxygenases, to increase the availability of peroxygenases, and to develop improved reaction concepts utilizing these enzymes. Working in cooperation with RWTH Aachen, TU Dresden, and University Hamburg, DECHEMA research institute will focus on improvements to heterologous expression systems in order to increase the availability of UPO. Moreover, the development of new reaction systems is a major goal of this project. With the goal of increasing productivity and stability, the application of UPO in combination with in situ hydrogen peroxide production will be investigated in detail.

 

CEEPOx- Entwicklung einer Systemlösung für chemo-elektro-enzymatische Percarbonsäure-vermittelte Oxidationsreaktionen am Beispiel der Erzeugung chiraler Monoterpene

Laufzeit: 1.1.2014 - 30.6.2016
Partner: Hochschule für Technik und Wirtschaft Berlin, TU Dresden
Geldgeber: AiF
Bearbeiter: Dirk Holtmann
Arbeitsgruppe: Industrielle Biotechnologie

Electroenzymatic reaction systems - through combination of electrochemistry and enzyme catalysis - afford a multitude of novel, resource-efficient production systems  

In combination with hydogen peroxide depent enzymes (peroxidases, peroxygenases, laccases, as well as (under specific conditions) lipases and P450 monooxygenases),  such systems exhibit a highly promising application potential. Use cases include the selective oxygenation by peroxidases, i.e. hydroxylations and epoxidations. Due to their wide substrate spectrum and their independance of cofactors, these enzymes are especially relevant for industrial use. In addition to chemical syntheses, their wide reaction spectrum also allows the application of such systems for removal of persistent environmental pollutants, e.g. in sewage treatmant plants. 

A downside of hydrogen peroxide dependant enzymes is their often law stability in the presence of hydrogen peroxide, which is one of the main factors why such enzymes are only sparingly used in todays industrial processes. The on-demand electrochemical production of hydrogen peroxide can be used to significantly increase the turnover number of these reactions while simultaneously maintaining high productivity. Preliminary work has identified gas diffusion electrodes (GDE) as especially promising electrodes for hydrogen peroxide production [1-4]. Through careful adjustment of electrical parameters, the hydrogen peroxide level can be maintained below the inhibitory level.

 

 1.         Getrey, L., et al., Enzymatic halogenation of the phenolic monoterpenes thymol and carvacrol with chloroperoxidase. Green Chemistry, 2014. 16(3): p. 1104-1108.

2.         Holtmann, D., et al., Electroenzymatic process to overcome enzyme instabilities. Catalysis Communications, 2014. 51(0): p. 82-85.

3.         Krieg, T., et al., Gas diffusion electrode as novel reaction system for an electro-enzymatic process with chloroperoxidase. Green Chemistry, 2011. 13(10): p. 2686-2689.

4.         Horst, A.E., K.M. Mangold, and D. Holtmann, Application of gas diffusion electrodes in bioelectrochemical syntheses and energy conversion. Biotechnology and Bioengineering, 2015.

5.         Horst, A.E., Bormann, S., Meyer, J.,  Steinhagen, M., Ludwig, R., Drews, A., Ansorge-Schumacher, M. and Holtmann, D., Electro-enzymatic hydroxylation of ethylbenzene by the evolved unspecific peroxygenase of Agrocybe aegerita. Journal of Molecular Catalysis B: Enzymatic, 2016.

 

Sustainable syntheses with CPO - Increasing reaction temperature, reactions in supercritical CO2 and new substrates

Period:   01.11.2013-31.10.2016
Partner:  ASA Spezialenzyme
Funder:  BMBF
Project Manager:  Sebastian Bormann
Research Group:  Industrial Biotechnology

The enzyme chloroperoxidase (CPO) which is naturally produced by the fungus Caldariomyces fumago is a versatile biocatalyst with an diverse array of potential applications for the oxyfunctionalization of organic substrates. In contrast to P450 monooxygenases which require the expensive cofactor NAD(P)H, CPO utilizes cheap hydrogen peroxide as a cobsubstrate.

Using rational design based protein engineering, CPO-variants with optimized reactivity for the peroxygenation of organic substrates have been produced in this project. Moreover, they were utilized in model reactions, including biocatalysis in supercritical carbon dioxide. Use of this solvent as an alternative reaction media can solve solubility problems that usually occur in aqueous system. In contrast to organic solvents, supercritical carbon dioxide is non-toxic, can be produced sustainably and is easy to dispose of. 

This project was carried out in cooperation with ASA Spezialenzyme. ASA is engaged in the development and production of various specialty enzymes and has extensive knowledge about formulation and utilization of chloroperoxidase.

 

back
Become a benefactor