ISSN:
1432-072X
Keywords:
Vanillic acid
;
Sporotrichum pulverulentum
;
Decarboxylation
;
Demethoxylation
;
Ring-cleavage
;
Laccase
;
Peroxidase
;
14CO2 evolution
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract In order to determine the influence of glucose on vanillate metabolism and how vanillic acid is prepared for ring-cleavage by the white-rot fungus Sporotrichum pulverulentum Nov., vanillate metabolism was studied using three different glucose-nitrogen media. When vanillate was added to cultures of S. pulverulentum oxidative decarboxylation occurred rapidly but was repressed by glucose. After the initial decarboxylation, methanol was detected as an early metabolic product appearing before 14CO2 release from 14C-ring-labelled vanillate. Methanol was also formed from methoxyhydroquinone in cultures of S. pulverulentum, and in vitro from vanillic acid on addition of purified laccase and peroxidase. It is proposed that the main pathway for vanillic acid degradation by S. pulverulentum involves decarboxylation to methoxyhydroquinone (MHQ). Demethoxylation of MHQ to a demethoxylated quinone is followed by enzymic reduction to give the tri-hydroxylated compound hydroxyquinol, which then undergoes ring-cleavage. The structure and fate of the ring-cleavage product maleylacetate has been clarified earlier in our laboratory.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00415600
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