Investigation of cellobiose dehydrogenase and lytic polysaccharide monooxygenase for application in industry

Background.

Enzymes are not yet used in chemical industry due to a lack of biocatalysts with the required selectivity, availability and compatibility with the rigorous process conditions. In this project cellobiose dehydrogenase (CDH) and lytic polysaccharide monooxygenase (LPMO) are investigated for its applicability in industry for the oxidation and oxifunctionalization of small molecules and polymeric substrates. The project is part of the Research project INDOX "Optimized oxidoreductases for medium and large scale industrial biotransformations". Cellobiose dehydrogenase (CDH) is the only known extracellular flavocytochrome and is secreted upon growth on lignocellulosic biomass by wood-degrading fungi from the phyla Basidiomycota and Ascomycota.

CDH is composed of a dehydrogenase domain and a cytochrome domain that are connected by a flexible linker. The substrate cellobiose is oxidized by CDH at the C1 position, the electrons are transferred from the dehydrogenase domain to the cytochrome domain and then to a final electron acceptor which is supposed to be LPMO (Ludwig, 2013). LPMO is a copper containing enzyme and has a boosting effect on enzymatic cellulose degradation in combination with cellulose cocktails. It is supposed to act on insoluble and crystalline cellulose that cannot be degraded by cellulases (Phillips, 2011).

Aims and methods.

The aim of the project is to screen and optimize biocatalysts for medium and large scale industrial processes. The screening of new biocatalysts is based on genome mining for CDH and LPMO. Starting from phylogenetic analysis, interesting and promising genes are selected for further investigation and will be recombinantly expressed and characterized. Promising candidates for industrial application will be altered by protein engineering towards industrial applicability which will then be examined in cooperation with partners of the research project in the course of research stays at institutions within the INDOX consortium.

Phillips CM, Beeson WT, Cate JH, Marletta MA. Cellobiose dehydrogenase and a copper-dependent polysaccharide monooxygenase potentiate cellulose degradation by Neurospora crassa. ACS Chem Biol 2011, 6:1399-406.
Ludwig R, Ortiz R, Schulz C, Harreither W, Sygmund C, Gorton L. Cellobiose dehydrogenase modified electrodes: advances by materials science and biochemical engineering. Anal Bioanal Chem 2013, 405(11):3637-3658