Substrate specificity of Myriococcum thermophilum cellobiose dehydrogenase on mono-, oligo-, and polysaccharides related to in situ production of H2O2

Abstract

Cellobiose dehydrogenase from the ascomycete fungus Myriococcum thermophilum (MtCDH) was tested for the ability to generate bleaching species at a pH suitable for liquid detergents. The catalytic properties of MtCDH were investigated for a large variety of carbohydrate substrates using oxygen as an electron receptor. MtCDH produces H2O2 with all substrates tested (except fructose) but only in the presence of a chelant. Insoluble substrates like cellulose and cotton could as well be oxidized by MtCDH. To enhance the amount of cello-oligosaccharides in solution, different cellulases on cotton were used and in combination with MtCDH an increased H2O2 concentration could be measured. Additionally, the degradation of pure anthocyanins in solution (as model substrates for bleaching) was investigated in the absence and presence of a horseradish peroxidase. MtCDH was able to produce a sufficient amount of H2O2 to decolorize the anthocyanins within 2 h.

Preventing microbial colonisation of catheters: Antimicrobial and antibiofilm activities of cellobiose dehydrogenase

“…Since CDH is able to oxidise a wide variety of oligosaccharides [28], it is believed that the enzymatically generated fragments were oxidised by CDH resulting in concomitant H 2 O 2 production as evidenced by an increased H 2 O 2 concentration especially when amylase-treated exPS were incubated with CDH. These enzymes are known to exhibit antimicrobial activities by degrading the biofilm matrix through the cleavage of ␣-linked glycosides, which are also present in exPS [16].…”

Analysis of myeloperoxidase activity in wound fluids as a marker of infection

“…A recently reported CDH (EC 1.1.99.15) from Myriococcum thermophilum which accepts a wide range of sugars and polysaccharides was used to produce hydrogen peroxide. 26 Indeed, it was possible to replace hydrogen peroxide in the assay solution by addition of this enzyme together with cellobiose.…”

“…CV þ is stable for several days. 25 Oxidation of LCV to crystal violet was carried out using an assay modified from the previously published method from Pricelius et al 26 The reaction mixture contained 5 mL sodium acetate buffer (200 mmol/L, pH 4.0) and 500 mL LCV (1 mmol/L in 0.06 M HCl). To 2 mL of reaction solution, 8 mL H 2 O 2 were added.…”

“…H 2 O 2 production was based on a modified method published by Pricelius et al 26 Essentially, the reaction mixtures as described above contained cellobiose (5 mmol/L), desferrioxamine mesylate (1 mmol/L) and 1.5 U/mL of CDH instead of hydrogen peroxide.…”

Fungal Strategies for Lignin Degradation

“…The heme part is also involved in electron transfer to a wide variety of substrates acting as electron acceptors including quinones (Henriksson et al, 2000a;Westermark and Eriksson, 1975), metal ions and organic dyes. When CDHs are reduced, the enzymes can react with dioxygen to produce hydrogen peroxide in situ (Pricelius et al, 2009).…”