Afonso, C M. M.

Amorim, Catarina L.

Carvalho, M. F.

Castro, P. M. L.

Janssen, D. B.

Moreira, I. S.

English

Repositório Institucional da Universidade Católica Portuguesa

Production of 4-fluorocatechol from fluorobenzene by the wild strain Labrys portucalensisI. S. Moreira1, M. F. Carvalho1, C. L. Amorim1, C. M. M. Afonso1Escola Superior de Biotecnologia, Universidade Católica Portuguesa,Porto, Portugal, 3 Groningen Biomolecular Sciences and BotechnologyIntroductionMicrobial production of catechols has been subject of investigationbecause of the advantages it may pose in comparison with organicsynthesis. 4-Fluorocatechol (4-FC) is formed as an intermediateduring fluorobenzene (FB) degradation by cell suspensions of Labrysportucalensis strain F11. The metabolism of this intermediateproceeds through ortho cleavage by a (fluoro)catechol 1,2-dioxygenase [1]. A strategy to possibly accumulate 4-FC by cells ofstrain F11 consist in the inhibition of catechol 1,2-dioxygenase by theaddition of chemical inhibitors.The aim of this work was to evaluate the effect of the addition of threedifferent inhibitors on FB degradation and on 4-FC accumulation.Results• LC-MS analysis showed higher accumulation of 4-FC, by cells induced with• The level of 4-FC accumulation was lower when AgNO3 was present (Fig. 1• FeSO4 had no effect on either FB degradation or on 4-FC accumulation (Figs• Induced cells of strain F11, in which ring-cleavage dioxygenase is inhibitedrequire cloning and recombinant overexpression of the dioxygenase gene, a1,01,20,8[4-FC] (mM)0,40,6[4-FC] (mM)0,2[4-FC] (mM)0,00 5 10 15 20 25 30 35Time (hours)Figure 1. 4-FC accumulation during FB degradation by Labrys portucalensis strain F11 restingcells suspended in KH2PO4-Na2HPO4 buffer with 1 mM ascorbic acid, 2.5 mM FB and: 1 mMAgNO3 ( ), 0.5 mM AgNO3 ( ),1mM CuSO4 ( ), 0.5 mM CuSO4 ( ), 1 mM FeSO4 ( ),0.5 mM FeSO4 ( ) and control without inhibitor ( ).AcknowledgementsI.S. Moreira and M.F. Carvalho wish to acknowledge a research grant from Fundação para a Ciência e Tecnologia (FCT), Portugalrespectively) and Fundo Social Europeu (III Quadro Comunitário de Apoio). This work was supported by the FCT Project References[1] M. F. Carvalho, M. I. M. Ferreira, I. S. Moreira, P. M. L. Castro, D. B. Janssen, Appl. Environ. Microbiol.2, D. B. Janssen3, P. M. L. Castro1Porto, Portugal; 2 Faculdade de Farmácia, Universidade do Porto,Institute, University of Groningen, Groningen, The NetherlandsMethodsCells of strain F11 pregrown on FB↓Harvested by centrifugation↓Washed and ressuspended in phosphate buffer↓2.5 mM FB • AgNO3 0.5 mM / 1 mM+1 mM ascorbic acid+ • CuSO4 0.5 mM / 1 mM• FeSO4 0.5 mM / 1 mM↓•  (control)Sampling: 4-FC formation/accumulation (LC-MS analysis) fluoride release (potenciometry)FB, when incubated in the presence of FB and CuSO4 (Fig. 1).), and Ag+ showed a stronger inhibiting effect on FB degradation (Fig. 2).. 1 and 2)., may be used for catechol accumulation, and further optimisation maywork which is ongoing.0,60,70,40,5[F] (mM)0,20,3[F] (mM)0,1[F] (mM)00 5 10 15 20 25 30 35Time (hours)Figure 2. Fluoride release during FB degradation by Labrys portucalensis strain F11 restingcells suspended in KH2PO4-Na2HPO4 buffer with 1 mM ascorbic acid, 2.5 mM FB and: 1 mMAgNO3 ( ), 0.5 mM AgNO3 ( ),1mM CuSO4 ( ), 0.5 mM CuSO4 ( ), 1 mM FeSO4 ( ),0.5 mM FeSO4 ( ) and control without inhibitor ( ).(Ref. SFRH/BD/28744/2006 and SFRH/BPD/14281/2003, - PTDC/BIO/67306/2006., 2006, 72, 7413.

Production of 4-fluorocatechol from fluorobenzene by the wild srain Labrys portucalensis

https://repositorio.ucp.pt/bitstream/10400.14/4782/1/com-inter_2008_ESB_361006004_Moreira_Irina.pdf

Production of 4-fluorocatechol from fluorobenzene by the wild srain Labrys portucalensis

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