TY - JOUR
T1 - Characterization of an isoproturon mineralizing bacterial culture enriched from a French agricultural soil
AU - Hussain, Sabir
AU - Sørensen, Sebastian R.
AU - Devers-Lamrani, Marion
AU - El-Sebai, Talaat
AU - Martin-Laurent, Fabrice
N1 - Funding Information:
The PhD work of Sabir Hussain was funded by Higher Education Commission, HEC (Pakistan) and The Doctoral School of the University of Burgundy (France). The work of Sebastian R. Sørensen was funded by the Center for Environmental and Agricultural Microbiology, CREAM , funded by the Willum Kann Rasmussen Foundation .
PY - 2009/11
Y1 - 2009/11
N2 - The phenylurea herbicide isoproturon, 3-(4-isopropylphenyl)-1,1-dimethylurea (IPU), was found to be rapidly mineralized by a bacterial culture isolated from an agricultural soil regularly exposed to IPU. Molecular analysis of the bacterial culture by DNA fingerprinting, cloning and sequencing of the 16S rRNA genes revealed that it consisted of six different members among whom the dominant was related to Sphingomonas sp. Six bacterial strains belonging to genera Ancylobacter, Pseudomonas, Stenotrophomonas, Methylobacterium, Variovorax and Agrobacterium were isolated from the IPU-degrading culture. None of these were able to degrade IPU in pure culture and only the intact culture sustained the ability to mineralize IPU. The composition of the culture appeared stable suggesting that yet unknown interactions are involved in the IPU mineralization. IPU degradation involved the transitory accumulation of three known IPU metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, and 4-isopropylaniline and their further degradation. Thus, it indicates a metabolic pathway initiated by two successive N-demethylations, followed by cleavage of the urea side chain. This culture did not degrade other structurally related phenylurea herbicides. The degrading activity of the bacterial culture was deeply influenced by the pH, being completely inhibited at pH 5.5 and optimal at pH 7.5.
AB - The phenylurea herbicide isoproturon, 3-(4-isopropylphenyl)-1,1-dimethylurea (IPU), was found to be rapidly mineralized by a bacterial culture isolated from an agricultural soil regularly exposed to IPU. Molecular analysis of the bacterial culture by DNA fingerprinting, cloning and sequencing of the 16S rRNA genes revealed that it consisted of six different members among whom the dominant was related to Sphingomonas sp. Six bacterial strains belonging to genera Ancylobacter, Pseudomonas, Stenotrophomonas, Methylobacterium, Variovorax and Agrobacterium were isolated from the IPU-degrading culture. None of these were able to degrade IPU in pure culture and only the intact culture sustained the ability to mineralize IPU. The composition of the culture appeared stable suggesting that yet unknown interactions are involved in the IPU mineralization. IPU degradation involved the transitory accumulation of three known IPU metabolites 3-(4-isopropylphenyl)-1-methylurea, 3-(4-isopropylphenyl)-urea, and 4-isopropylaniline and their further degradation. Thus, it indicates a metabolic pathway initiated by two successive N-demethylations, followed by cleavage of the urea side chain. This culture did not degrade other structurally related phenylurea herbicides. The degrading activity of the bacterial culture was deeply influenced by the pH, being completely inhibited at pH 5.5 and optimal at pH 7.5.
KW - Bacterial culture
KW - Isoproturon
KW - Metabolites
KW - Mineralization
KW - pH regulation
UR - http://www.scopus.com/inward/record.url?scp=71449091617&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2009.09.020
DO - 10.1016/j.chemosphere.2009.09.020
M3 - Article
SN - 0045-6535
VL - 77
SP - 1052
EP - 1059
JO - Chemosphere
JF - Chemosphere
IS - 8
ER -