OPTIMAL CONDITIONS FOR BIOCONVERSION OF FERULIC ACID INTO VANILLIC ACID BY PSEUDOMONAS-FLUORESCENS BF13 CELLS

Pseudomonas fluorescens BF13 is especially capable of promoting the fo rmation of vanillic acid during ferulic acid degradation. We studied t he possibility of enhancing the formation of this intermediary metabol ite by using suspensions of cells at high density. The bioconversion o f ferulic into vanillic acid was affected by several parameters, such as the concentration of the biomass, the amount of ferulic acid that w as treated, the carbon source on which the biomass was grown. The opti mal yield of vanillic acid was obtained with 6 mg/ml cells pre-grown o n p-coumaric acid and 2 mg/ml ferulic acid. Under these conditions the bioconversion rate was 95% in 5 h. Therefore BF13 strain represents a valid biocatalyst for the preparative synthesis of vanillic acid.