Characterization of the isoproturon degrading community : from the field to the genes
type: Dataset
description: Frequent use of phenylurea herbicide isoproturon (IPU) in agricultural fields has resulted not only in the contamination of the natural resources including soil and water but also in the adaptation of the soil microflora to its rapid degradation. However, up to now, the mechanisms underlying this microbial adaptation are not well elucidated. The aim of this study was to explore the processes and factors implicated in IPU degradation from the agricultural field to the genes coding for catabolic genes. The study carried out at the experimental field of Epoisses cropped with a winter wheat / barley / rape seed crop rotation indicated that as a result of its periodically repeated use, the soil microflora adapted to IPU mineralization activity. Further analysis using exploratory and geostatistical tools demonstrated the existence of spatial variability in IPU mineralization activity at the field scale which was correlated not only with several soil physico-chemical parameters like organic matter content, CEC and C/N ratio but also with the pesticide application plan over a three year crop rotation. In order to get further insight into underlying mechanisms, an IPU mineralizing bacterial culture and strain Sphingomonas sp. SH were isolated through enrichment cultures performed from two different adapted soils. Both had the catabolic activities highly specific for the mineralization of IPU and its metabolites but none of other structurally related phenylurea herbicides. IPU metabolic activity of both the mixed culture and the strain SH was found to be affected by pH with optimal activity taking place at pH 7.5. Based on the accumulation of different known metabolites during mineralization kinetics, IPU metabolic pathway was proposed to be initiated by two successive demethylations, followed by cleavage of the urea side chain resulting in the accumulation of 4-isopropylaniline, and ultimately the mineralization of the phenyl ring. In order to identify the genes involved in …
identifier: NNT: 2010DIJOS076
issued: 2026-05-27T00:35:43.996467
language: en
modified: 2026-05-27T00:35:43.996472
contact point: Organization
  fn: CCSD
keyword: 1_
keyword: 2-dioxygenase
keyword: bac-cloning
keyword: biodegradation
keyword: clonage-bac
keyword: herbicide
keyword: herbicides
keyword: infoeu-reposemanticsdoctoralthesis
keyword: isoproturon
keyword: metabolic-pathway
keyword: microbiologie-du-sol
keyword: sdvsalife-sciences-q-bioagricultural-sciences
keyword: soil-microbiology
keyword: spatial-variability
keyword: theses
keyword: variabilite-spatiale
keyword: voie-metabolique
landing page: https://theses.hal.science/tel-00674042

Characterization of the isoproturon degrading community : from the field to the genes
type: Distribution
format: HTML
issued: 2026-05-27T00:35:44.102255
modified: 2026-05-27T00:35:43.958031
access URL: https://theses.hal.science/tel-00674042

test_moissonnage_selune
type: Agent