BIOCONVERSION OF VANILLIN INTO VANILLIC ACID BY PSEUDOMONAS-FLUORESCENS STRAIN BTP9 - CELL REACTORS AND MUTANTS STUDY

The ability of a fluorescent Pseudomonas to bioconvert vanillin, a phenolic compound, into vanillic acid was investigated. Free and immobilized cell reactors were tested. With free cells, the optimal yield reaches 98% after 6 h and 30 min of bioconversion. With cells immobilized in alginate beads, transformation rate is only 47% after 13 h of conversion. Nevertheless, a continuous immobilized cell reactor was used for 76 h. With this one, the optimal yield is higher than 80%. The influence of the residence time and cell concentration of the alginate beads in the reactor over the reactor's productivity has also been studied. Catabolically blocked mutants for vanillic acid degradation were searched. To screen these mutants, a new and very sensitive method was reported. The results of our mutant screenings were discussed.