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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Insights into the microbial degradation pathways of the ioxynil octanoate herbicide

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Oliveira, Karina O. [1] ; Silva, Amanda R. M. [2] ; da Silva, Bianca F. [1] ; Milagre, Humberto M. S. [1] ; Milagre, Cintia D. F. [1]
Total Authors: 5
[1] UNESP Sao Paulo State Univ, Inst Chem, BR-14800060 Araraquara, SP - Brazil
[2] Univ Sao Paulo, Inst Chem, BR-05508000 Sao Paulo, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Web of Science Citations: 2

This paper describes the biodegradation of the ioxynil octanoate herbicide by indigenous microorganisms isolated from herbicide impacted soil-enrichment cultures. Eleven positive hits out of twenty-nine microorganisms screened for nitrile hydratase, nitrilase and amidase activity were further evaluated based on their growth in microtiter plates containing liquid medium with increasing concentrations of herbicide (0.97-250 mM). Two strains were selected from this assay for biodegradation studies and were identified as Lysinibacillus boronitolerans MLH-31 and Bacillus cereus MLH-61. The bacterial degradation of ioxynil octanoate and its biodegradation products were monitored, identified and characterized by liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In addition to 3,5-diiodo-4-hydroxybenzamide and 3,5-diiodo-4-hydroxybenzoic acid, which are commonly detected metabolites, two new metabolites were observed: mono-deiodinated compound 3-iodo-4-hydroxybenzoic acid and the product of Caromatic-CN cleaved 1,3-diiodophenol. The experimentally observed metabolites were correlated with the enzymatic systems involved, revealing the presence of esterases, nitrile hydratases, amidases, nitrilases, dehalogenases and carbon-carbon lyases during biodegradation. Lysinibacillus boronitolerans MLH-31 was found to degrade ioxynil octanoate at a rate of 97% over 7 days through a batch-resting cells experiment, while Bacillus cereus MLH-61 was found to do so at a rate of 75% under the same conditions. (AU)

FAPESP's process: 10/02305-5 - Microbial nitrile transformations: prospection for microorganisms, synthesis of chiral bioactive compounds and biodegradation
Grantee:Cintia Duarte de Freitas Milagre
Support type: Research Grants - Young Investigators Grants
FAPESP's process: 14/50249-8 - Green chemistry: sustainable synthetic methods employing benign solvents, safer reagents, and bio-renewable feedstock
Grantee:Arlene Gonçalves Corrêa
Support type: Research Grants - Research Centers in Engineering Program