Bioconversion of Ferulic Acid to 4-Vinylguaiacol by Ferulic Acid Decarboxylase from Brucella intermedia TG 3.48

Abstract

4-vinylguaiacol (4-VG) is a commercially important compound due to its characteristic clove-like aroma and its use as a flavoring in the food, beverage, and cosmetics industries. However, its extraction from natural sources or by a chemical method is expensive. The bioconversion of ferulic acid (FA) to 4-VG via microorganisms is an alternative, considering the market trend toward biotechnological and environmentally friendly processes and products. This study aimed to evaluate the tolerance of the bacterial strain Brucella intermedia (basonym Ochrobactrum intermedium) TG 3.48 to FA, its bioconversion to 4-VG, and the activity of the FA decarboxylase enzyme (FADase), which is key to the 4-VG production process. The strain tolerated FA concentrations up to 700 mg L−1. When the microorganism grew at 300 mg L−1 FA in Mineral Liquid Medium (MLM), it converted 99.5% of FA to 4-VG within 12 h. The FADase activity was cell-associated with 5.17 U mL-1 in the whole cell, 4.40 U mL−1 in the intracellular extract, and 3.54 U mL−1 in the cell wall fragments, while the specific activity was 778.90 U mg−1.