Miri, Saba; Rasooli, Azadeh; Brar, Satinder Kaur; Rouissi, Tarek et Martel, Richard 
ORCID: https://orcid.org/0000-0003-4219-5582
(2022).
Biodegradation of p-xylene—a comparison of three psychrophilic Pseudomonas strains through the lens of gene expression.
Environmental Science and Pollution Research
, vol. 29
, nº 15.
pp. 21465-21479.
DOI: 10.1007/s11356-021-17387-5.
Résumé
p-Xylene is considered a recalcitrant compound despite showing a similar aromatic structure to other BTEXs (benzene, toluene, ethylbenzene, xylene isomers). This study evaluated the p-xylene biodegradation potential of three psychrophilic Pseudomonas strains (Pseudomonas putida S2TR-01, Pseudomonas synxantha S2TR-20, and Pseudomonas azotoformans S2TR-09). The p-xylene metabolism-related catabolic genes (xylM, xylA, and xylE) and the corresponding regulatory genes (xylR and xylS) of the selected strains were investigated. The biodegradation results showed that the P. azotoformans S2TR-09 strain was the only strain that was able to degrade 200 mg/L p-xylene after 60 h at 15 °C. The gene expression study indicated that the xylE (encoding catechol 2,3-dioxygenase) gene represents the bottleneck in p-xylene biodegradation. A lack of xylE expression leads to the accumulation of intermediates and the inhibition of biomass production and complete carbon recovery. The activity of xylene monooxygenase and catechol 2,3-dioxygenase was significantly increased in P. azotoformans S2TR-09 (0.5 and 0.08 U/mg, respectively) in the presence of p-xylene. The expression of the ring cleavage enzyme and its encoding gene (xylE) and activator (xylS) explained the differences in the p-xylene metabolism of the isolated bacteria and can be used as a novel biomarker of efficient p-xylene biodegradation at contaminated sites.
| Type de document: | Article |
|---|---|
| Mots-clés libres: | catechol 2,3-dioxygenase; gene expression; p-Xylene; xylE |
| Centre: | Centre Eau Terre Environnement |
| Date de dépôt: | 23 juin 2022 14:35 |
| Dernière modification: | 23 juin 2022 14:35 |
| URI: | https://espace.inrs.ca/id/eprint/12700 |
Gestion Actions (Identification requise)
 |
Modifier la notice |