Intermediate accumulation of metabolites results in a bottleneck for mineralisation of the herbicide metabolite 2,6-dichlorobenzamide (BAM) by Aminobacter spp.

TY - JOUR

T1 - Intermediate accumulation of metabolites results in a bottleneck for mineralisation of the herbicide metabolite 2,6-dichlorobenzamide (BAM) by Aminobacter spp.

AU - Simonsen, Allan

AU - Badawi, Nora

AU - Anskjær, Gitte Gotholdt

AU - Albers, Christian N.

AU - Sørensen, Sebastian R.

AU - Sørensen, Jan

AU - Aamand, Jens

PY - 2012/4

Y1 - 2012/4

N2 - Degradation and mineralisation of the groundwater contaminant 2,6-dichloro-benzamide (BAM) was investigated in two Aminobacter strains focussing on the induction of BAM degradation and mineralisation and occurrence of intermediate metabolites. The BAM degradation rate was independent of whether the cells were pre-grown in the absence or presence of BAM, thus indicating that the first step in the degradation pathway was constitutively expressed. In contrast, 14CO2 production was stimulated when cells were pre-grown in the presence of BAM, suggesting that one or more of the subsequent steps in the degradation pathway were inducible. Accumulation of 2,6-dichlorobenzoate (DCBA) during degradation of BAM demonstrated that the first step involved amidase activity. Mass balance calculations and thin-layer chromatography coupled with autoradiographic detection indicated that degradation of DCBA and at least one unknown metabolite may comprise a bottleneck for BAM mineralisation by Aminobacter spp. The study thus provides novel information about the BAM degradation pathway and points to the involvement of unknown intermediate metabolites in degradation of this important groundwater contaminant.

AB - Degradation and mineralisation of the groundwater contaminant 2,6-dichloro-benzamide (BAM) was investigated in two Aminobacter strains focussing on the induction of BAM degradation and mineralisation and occurrence of intermediate metabolites. The BAM degradation rate was independent of whether the cells were pre-grown in the absence or presence of BAM, thus indicating that the first step in the degradation pathway was constitutively expressed. In contrast, 14CO2 production was stimulated when cells were pre-grown in the presence of BAM, suggesting that one or more of the subsequent steps in the degradation pathway were inducible. Accumulation of 2,6-dichlorobenzoate (DCBA) during degradation of BAM demonstrated that the first step involved amidase activity. Mass balance calculations and thin-layer chromatography coupled with autoradiographic detection indicated that degradation of DCBA and at least one unknown metabolite may comprise a bottleneck for BAM mineralisation by Aminobacter spp. The study thus provides novel information about the BAM degradation pathway and points to the involvement of unknown intermediate metabolites in degradation of this important groundwater contaminant.

U2 - 10.1007/s00253-011-3591-x

DO - 10.1007/s00253-011-3591-x

M3 - Journal article

C2 - 21983704

SN - 0175-7598

VL - 94

SP - 237

EP - 245

JO - Applied Microbiology and Biotechnology

JF - Applied Microbiology and Biotechnology

IS - 1

ER -