Metabolic pathways of degradation of malvidin-3-O-monoglucoside by Candida oleophila

Abstract

This work proposes an initial approach to the biodegradation pathway of coloured monomeric compounds found in wine, specifically malvidin-3-O-monoglucoside (Mv3G) using a Candida oleophila isolate, and the identification of the resulting degradation products. Three different concentrations of Mv3G were tested (1.0, 0.5 and 0.25 g/L) as single carbon and energy source for the growth of yeasts in the biodegradation assay throughout 14 days with samples being taken at different stages (0, 7 and 14 days). The results showed that the yeast was responsible for the decrease of about 30% of the initial concentration of Mv3G for the highest concentrations tested (1.0 g/L, 0.5 g/L), and about 11% in the lowest concentration (0.25 g/L). The main metabolite identified by HPLC-DAD-MS was syringic acid. Moreover, enzymatic assays have showed the activity of catechol-2,3-dioxygenase, which is compatible with a meta-ring cleavage of the phenolic compound's resultant from the biodegradation process. A wild isolate of the species Candida oleophila was used as biological model, to ascertain if coloured compounds found in wine follow the same metabolic pathway of degradation as benzene derivatives.