In situ generation of hydrogen peroxide by carbohydrate oxidase and cellobiose dehydrogenase for bleaching purposes

Abstract

The carbohydrate oxidase from Microdochium nivale (CAOX), heterologously expressed in Aspergillus oryzae, and cellobiose dehydrogenase from Myriococcum thermophilum (MtCDH), were assessed for their ability to generate bleaching species at a pH suitable for liquid detergents. The substrate specificities of CAOX and MtCDH were analyzed on a large variety of soluble and insoluble substrates, using oxygen as an electron receptor. Even insoluble substrates like cellulose were oxidized from both CAOX and MtCDH, but only MtCDH produced H₂O₂ on cotton as the sole substrate. To enhance the amount of cello-oligosaccharides formed from cotton as substrates for CAOX and MtCDH, various cellulases were used in combination with MtCDH or CAOX, leading to a 10-fold increase in H₂O₂. As model substrates for colored stains, the degradation of pure anthocyanins and stain removal of blueberry stains by CAOX and MtCDH was examined in the absence and presence of a horseradish peroxidase. Both enzymes were able to produce an amount of H₂O₂ sufficient to decolorize the pure anthocyanins within 2 h and showed significant cleaning benefits on the stains.

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

“…Furthermore, the extracted exPS were hydrolysed separately using 3 U/mL of either ␣-amylase, endoglucanase, mannanase or pulpzyme supplemented with 500 L of exPS. Samples were incubated at 50 • C while shaking at 400 rpm for 24 h. The exPS hydrolysates were then incubated with CDH while monitoring H 2 O 2 production using a modified leucocrystal violet assay described by Pricelius et al [17]. Briefly, 100 L of CDH (0.5 U/mL) was incubated with 555 L of sodium phosphate buffer (55 mM, pH 6.5) and 100 L of hydrolysed exPS for 30 min at 40 • C and 600 rpm in a ThermoMixer ® (Eppendorf, Hamburg, Germany).…”

“…The mixture was then incubated at 99 • C for 10 min to inactivate both the CDH and the hydrolytic enzymes. The H 2 O 2 produced was measured as described by Pricelius et al [17].…”

“…CDH is an oxidoreductase that, unlike glucose oxidase, can oxidise cello-oligosaccharides (including cellobiose) and other oligosaccharides to produce H 2 O 2 , which are not growth substrates for many micro-organisms causing infections [15,16]. In addition, CDH oxidation of cello-oligosaccharides produces cellobionic acid, which lowers the pH thereby creating a hostile environment for bacteria [15,17]. This study therefore investigated the possibility of using CDH as an antimicrobial and antibiofilm agent to prevent urinary catheter-based infections.…”

Semi-rational engineering of cellobiose dehydrogenase for improved hydrogen peroxide production

“…A more recent proposed application of CDH has been the in situ production of H 2 O 2 for cotton bleaching [10,17,18]. CDH has the potential to replace the currently used mixture of H 2 O 2 and NaOCl, which causes damage to the cotton fibres, forms toxic by-products and consumes large amounts of energy and water.…”

Activity of carbohydrate oxidases as influenced by wheat flour dough components

“…This oxidase can be considered as safe for use in human food (Ahmad, Brinch, Friis, & Pedersen, 2004). COXMn can also be used in biosensors for glucose determination in blood (Kulys, Tetianec, & Schneider, 2000), in the catalysis of the biotransformation of lactose into the value-added product lactobionic acid (Nordkvist, Nielsen, & Villadsen, 2007), in the generation of bleaching agents in liquid detergents (Pricelius, Ludwig, Lant, Haltrich, & Guebitz, 2011) and as a dough or bread improver (Arnaut, De Meyer, & Van Haesendonck, 2006;Christensen et al, 1999;Oestergaard & De Maria, 2011).…”