Creation of metal-complexing agents, reduction of manganese dioxide, and promotion of manganese peroxidase-mediated Mn(III) production by cellobiose:quinone oxidoreductase from Trametes versicolor.
Culture supernatants of the white-rot fungus Trametes versicolor were found to contain Mn(III)-complexing agents able to effectively promote manganese-dependent peroxidase (MnP)-mediated oxidation of phenol red. The high molecular weight fractions of these supernatants contained carbohydrate polymers that functioned as effective Mn(III)-complexing agents. Gluconic and glucuronic acids were also found to be effective Mn(III)-complexing ligands capable of supporting MnP-mediated phenol red oxidation, as was the cellobionic acid formed from cellobiose by cellobiose:quinone oxidoreductase (CBQase) (EC 1.1.5.1). The formation of cellulose-derived sugar acid manganese-complexing agents by CBQase increased in the presence of wood pulp and cellulolytic enzymes. CBQase, while oxidizing cellobiose, reduced insoluble Mn(IV)O2 to Mn(II) or Mn(III) by a reaction whose rate is determined by the nature of the manganese-complexing agents present. A model is proposed to explain how oxidation of carbohydrate and reduction of MnO2 and quinones by CBQase may complement oxidation by MnP, thus promoting lignin biodegradation.
Roy
B P
BP
Pulp and Paper Research Institute of Canada, Pointe Claire, Quebec.
Paice
M G
MG
Archibald
F S
FS
Misra
S K
SK
Misiak
L E
LE
D000143:Acids; D002237:Carbohydrate Dehydrogenases / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D008345:Manganese / Q000378:metabolism*; D017895:Manganese Compounds / Q000378:metabolism*; D010084:Oxidation-Reduction; D010087:Oxides / Q000378:metabolism*; D010544:Peroxidases / Q000378:metabolism*; D011124:Polyporaceae / Q000201:enzymology*
D000143:Acids; D017895:Manganese Compounds; D010087:Oxides; D008345:Manganese; D002482:Cellulose; D002237:Carbohydrate Dehydrogenases; C019859:cellobiose-quinone oxidoreductase; D010544:Peroxidases; C051129:manganese peroxidase; C016552:manganese dioxide