@article{fdi:010049099,
  title = {{H}ydroxytyrosol from tyrosol using hydroxyphenylacetic acid-induced bacterial cultures and evidence of the role of 4-{HPA} 3-hydroxylase},
  author = {{L}iebgott, {P}-{P}. and {A}mouric, {A}. and {C}omte, {A}. and {T}holozan, {J}ean-{L}uc and {L}orquin, {J}ean},
  editor = {},
  language = {{ENG}},
  abstract = {{H}ydroxytyrosol ({HT}yr) is a potent natural antioxidant found in olive mill wastewaters. {B}acterial conversion of 4-tyrosol (2-(4-hydroxyphenyl)-ethanol) to {HT}yr was reported in a limited number of bacterial species including {P}seudomonas aeruginosa. {I}n this work, we studied this conversion, taking as a model the newly isolated {H}alomonas sp. strain {HTB}24. {I}t was first hypothesized that the enzyme responsible for 4-tyrosol hydroxylation in {HT}yr was a 4-hydroxyphenylacetic acid 3-hydroxylase ({HPAH}, {EC} 1.14.13.3), previously known to convert 4-hydroxyphenylacetic acid (4-{HPA}) into 3,4-dihydroxyphenylacetic acid (3,4-{DHPA}) in {P}. aeruginosa. {C}loning and expression of hpa{B} (oxygenase component) and hpa{C} (reductase component) genes from {P}. aeruginosa confirmed this hypothesis. {F}urthermore, using cultures of {HTB}24 containing 4-tyrosol, it was shown that 4-{HPA} accumulation preceded 4-tyrosol hydroxylation. {W}e further demonstrated that the synthesis of {HPAH} activity was induced by 4-{HPA}, with the latter compound being formed from 4-tyrosol oxidation by aryl-dehydrogenases. {I}nterestingly, similar results were obtained with other 4-{HPA}-induced bacteria, including {P}. aeruginosa, {S}erratia marcescens, {E}scherichia coli, {M}icrococcus luteus and other {H}alomonas, thus demonstrating general hydroxylating activity of 4-tyrosol by the {HPAH} enzyme. {E}. coli {W} did not have aryl-dehydrogenase activity and hence were unable to oxidize 4-tyrosol to 4-{HPA} and {HT}yr to 3,4-{DHPA}, making this bacterium a good candidate for achieving better {HT}yr production.},
  keywords = {{H}ydroxytyrosol ; {T}yrosol ; {I}nduction ; 4-hydroxyphenylacetic acid ; 4-{HPA} ; 3-hydroxylase},
  booktitle = {},
  journal = {{R}esearch in {M}icrobiology},
  volume = {160},
  numero = {10},
  pages = {757--766},
  ISSN = {0923-2508},
  year = {2009},
  DOI = {10.1016/j.resmic.2009.09.015},
  URL = {https://www.documentation.ird.fr/hor/fdi:010049099},
}