Rapid conversion of ferulic acid to 4-vinyl guaiacol and vanillin metabolites by Debaryomyces hansenii

Debaryomyces hansenii, an isolated yeast strain metabolized ferulic acid to an intermediate compound, namely 4-vinyl guaiacol, by the non oxidative decarboxylation of its side chain. This bioconversion is a highly value added process as 4-vinyl guaiacol is nearly 40 times costlier than ferulic acid. The major degradation products were isolated and identified by thin layer chromatography, high performance liquid chromatography and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. Debaryomyces produced 1470 mg l−1 of vinyl guaiacol at the tenth hour itself, corresponding to a molar yield of 95% while the production of vanillin reached a maximum of 169 mg l−1 at the fifth hour.