Oxidative decarboxylation of vanillic acid by Sporotrichum pulverulentum

Aromatic ring cleavage by the white‐rot fungus Sporotrichum pulverulentum

“…NAD(P)Hdependent oxidative decarboxylation of vanillate to methoxyhydroquinone by partially 260 purified mycelial extracts has been reported [4]. However, we are unable to demonstrate hydroxylation or demethylation of the reaction product although extracts of mycelia grown in the presence of methoxyhydroquinone contain low levels of induced hydroxyquinol 1,2-dioxygenase.…”

“…Conditions for the cultivation of S. pulverulentum and the preparation of mycelial extracts have been described previously [4]. Where dioxygenase levels were compared in extracts of mycelia grown in the presence of vanillate or methoxyhydroquinone the fungus was cultured initially on glucose and sterile solutions of the aromatic compound (1 mM final concentration) were added after 24 h. Mycelial pellets were harvested after a further 18 h cultivation.…”

“…It is conceivable that vanillate itself is hydroxylated prior to the oxidative decarboxylation step which subsequently provides the third hydroxyl necessary for ring cleavage. Several compounds with a hydroxyl group para to a carboxyl substituent serve as substrates for the decarboxylating enzyme [4].…”

“…In an investigation of vanillic acid catabolism by Sporotrichum pulverulentum we have demonstrated an enzyme which catalyses the oxidative decarboxylation of vanillate to methoxyhydroquinone [4]. However, no further conversion of methoxyhydroquinone or cleavage of the benzene nucleus was observed using cell-free systems even though 14C02 is released from ring-labelled vanillate in growing cultures [S].…”

Characterization of the 5-Carboxyvanillate Decarboxylase Gene and Its Role in Lignin-Related Biphenyl Catabolism in Sphingomonas paucimobilis SYK-6

“…The other is the oxidative decarboxylase, which catalyzes hydroxylation and requires NAD(P)H for its enzymatic activity. For example, vanillate hydroxylase, which is a flavoprotein, catalyzes decarboxylation by concomitant hydroxylation at the relevant carbon atom (4,5). LigW does not require any cofactor for its activity, and MS analysis of the product from the reaction with D 2 O clearly indicated that one deuterium atom was incorporated into vanillate from D 2 O.…”