Use of Whole Cells ofPseudomonas aeruginosafor Synthesis of the Antioxidant Hydroxytyrosol via Conversion of Tyrosol

Abstract

For the first time, a soil bacterium, designated Pseudomonas aeruginosa, was isolated based on its ability to grow on tyrosol as a sole source of carbon and energy. During growth on tyrosol, this strain was capable of promoting the formation of a significant amount of hydroxytyrosol and trace quantities of parahydroxyphenyl acetic acid and 3,4-dihydroxyphenyl acetic acid. The products were confirmed by high-performance liquid chromatography and gas chromatography-mass spectrometry analyses. Using an optimized tyrosol concentration of 2 g liter ؊1 , the maximal hydroxytyrosol yield (80%) was achieved after a 7-h reaction in a growth experiment. To enhance the formation of hydroxytyrosol and prevent its degradation, a resting-cell method using P. aeruginosa was performed. The growth state of the culture utilized for biomass production, the carbon source on which the biomass was grown, the concentration of the biomass, and the amount of tyrosol that was treated were optimized. The optimal yield of hydroxytyrosol (96%) was obtained after a 7-h reaction using 4 g of tyrosol liter؊1 and 5 g of cells liter ؊1 pregrown on tyrosol and harvested at the end of the exponential phase. This proposed procedure is an alternative approach to obtain hydroxytyrosol in an environmentally friendly way. In addition, the reaction is easy to perform and can be adapted to a bioreactor for industrial purposes.

Involvement of antioxidant activity of Lactobacillus plantarum on functional properties of olive phenolic compounds

“…5b) in the presence of L. plantarum LAB 1. Allouche et al (2004) showed that Pseudomonas aeruginosa transforms the tyrosol into hydroxytyrosol, during the phase of adaptation of growth, without consumption of these aromatic compounds. After this period, the concentration of the hydroxytyrosol decreases in the medium but the degradation of the aromatic compounds Fig.…”

Use of Pseudomonas mendocina, or recombinant Escherichia coli cells expressing toluene-4-monooxygenase, and a cell-free tyrosinase for the synthesis of 4-fluorocatechol from fluorobenzene

“…Substituted catechols (diphenols) are important aromatic compounds and are widely used as synthons in industrial processes such as the manufacture of plastics, polymers, drugs and dyes (Allouche et al 2004;Held et al 1998;Pialis and Saville 1998;Tao et al 2004a, b). Site-specific hydroxylation of the aromatic ring for the production of these compounds can be a challenging process using conventional organic synthesis (Allouche et al 2004;Robinson et al 1992;Tao et al 2004a, b).…”

“…Site-specific hydroxylation of the aromatic ring for the production of these compounds can be a challenging process using conventional organic synthesis (Allouche et al 2004;Robinson et al 1992;Tao et al 2004a, b). These reactions often employ expensive starting materials and exhibit poor regiospecificity resulting in low product yield (Held et al 1998;Robinson et al 1992;Tao et al 2004a).…”

“…These reactions often employ expensive starting materials and exhibit poor regiospecificity resulting in low product yield (Held et al 1998;Robinson et al 1992;Tao et al 2004a). This limitation has lead to increased interest in the microbial synthesis of these compounds (Allouche et al 2004;Fishman et al 2004;Tao et al 2004a, b).…”

Desulfovibrio marrakechensis sp. nov., a 1,4-tyrosol-oxidizing, sulfate-reducing bacterium isolated from olive mill wastewater

“…1,4-Tyrosol is one of the major simple aromatic compounds present in OMW (Fernandez-Bolanos et al, 1998;Mulinacci et al, 2001) and exhibits toxicity towards several micro-organisms (Capasso et al, 1995;Sayadi et al, 2000). It has been reported that only aerobic bacteria under oxic conditions are able to oxidize 1,4-tyrosol (Allouche et al, 2004;Abdelkafi et al, 2005;Liebgott et al, 2007).…”