0000000000082423
AUTHOR
Talaat El Sebaï
Diuron mineralisation in a Mediterranean vineyard soil: impact of moisture content and temperature
BACKGROUND: The diuron-mineralising ability of the microbiota of a Mediterranean vineyard soil exposed each year to this herbicide was measured. The impact of soil moisture and temperature on this microbial activity was assessed. RESULTS: The soil microbiota was shown to mineralise diuron. This mineralising activity was positively correlated with soil moisture content, being negligible at 5% and more than 30% at 20% soil moisture content. According to a double Gaussian model applied to fit the dataset, the optimum temperature/soil moisture conditions were 27.9 °C/19.3% for maximum mineralisation rate and 21.9 °C/18.3% for maximum percentage mineralisation. The impact of temperature and soil…
Isolation and characterisation of an isoproturon-mineralisingMethylopilasp. TES from French agricultural soil
Using enrichment culture three isoproturon (IPU) mineralising bacterial isolates were isolated from a French agricultural soil mineralising up to 50% of the initially added 14C-ring labelled IPU within only eight days. These isolates showed similar metabolic (BIOLOG GN) and amplified rDNA restriction (ARDRA) profiles. Partial 16S rDNA sequencing revealed that they were identical and identified as Methylopila sp TES. This strain harbours a large plasmid (220 kb) putatively bearing essential IPU-degrading genes as demonstrated by a curing experiment. Methylopila sp. TES transformed IPU and its known metabolites to CO2 and biomass but did not degrade chlorotoluron, monolinuron, diuron and linu…