%0 Journal Article %T Dissipation of butachlor by a new strain of Pseudomonas sp. isolated from paddy soils %J Pollution %I University of Tehran %Z 2383-451X %A Pourbabaei, A. A. %A Khoshhal Nakhjiri, E. %A Torabi, E. %A Farahbakhsh, M. %D 2020 %\ 07/01/2020 %V 6 %N 3 %P 627-635 %! Dissipation of butachlor by a new strain of Pseudomonas sp. isolated from paddy soils %K Bacterial isolate %K bioremediation %K Pseudomonas aeruginosa %K Paddy %K Soil respiration %R 10.22059/poll.2020.299245.762 %X Butachlor (BUT) is a chloroacetanilide herbicide widely applied to rice paddies to control annual grass and broad-leaf weeds. A BUT-degrading bacterial strain (PK) was isolated from paddy soils. Biochemical and 16S rRNA sequencing characteristics confirmed the strain as Pseudomonas aeruginosa (99% resemblance). The isolate dissipated BUT (100 μg/mL) in an M9 liquid medium with a rate of 0.5 ± 0.03 day-1 and DT50 and DT90 of 1.38 ± 0.10 days and 4.58 ± 0.32 days, respectively. Soil dissipation of BUT was investigated under flooded conditions. In sterile soils, the isolate increased the dissipation of BUT (200 μg/g) (DT50 = 12.38 ± 1.83 days, DT90 = 41.12 ± 6.09 days, k = 0.06 ± 0.01 day-1) compared to sterile non-inoculated samples (DT50 = 26.87 ± 2.82 days, DT90 = 89.25 ± 9.36 days, k = 0.03 ± 0.00 day-1). In non-inoculated non-sterile soil experiments, the dissipation of BUT was faster (DT50 = 15.17 ± 2.11 days, DT90 = 50.38 ± 7.02 days, k = 0.05 ± 0.00 day-1) compared to non-inoculated sterile ones, and inoculating the isolate accelerated the removal of BUT in non-sterile soils significantly (DT50 = 8.03 ± 1.20 days, DT90 = 26.68 ± 3.97 days, k = 0.09 ± 0.01 day-1). BUT inhibited soil respiration (SR) initially for 5 days, followed by an increase until day 20. The increase in SR was more pronounced in the co-presence of BUT and the isolate. The results of this research suggest P. aeruginosa PK as a suitable candidate for BUT bioremediation. %U https://jpoll.ut.ac.ir/article_76559_d0f3245891440fe78d9e542930fdb0b8.pdf