Isolation and characterization of butachlor-catabolizing bacterial strain Stenotrophomonas acidaminiphila JS-1 from soil and assessment of its biodegradation potential.
OBJECTIVE
Isolation, characterization and assessment of butachlor-degrading potential of bacterial strain JS-1 in soil.


RESULTS
Butachlor-degrading bacteria were isolated using enrichment culture technique. The morphological, biochemical and genetic characteristics based on 16S rDNA sequence homology and phylogenetic analysis confirmed the isolate as Stenotrophomonas acidaminiphila strain JS-1. The strain JS-1 exhibited substantial growth in M9 mineral salt medium supplemented with 3.2 mmol l(-1) butachlor, as a sole source of carbon and energy. The HPLC analysis revealed almost complete disappearance of butachlor within 20 days in soil at a rate constant of 0.17 day(-1) and half-life (t((1/2))) of 4.0 days, following the first-order rate kinetics. The strain JS-1 in stationary phase of culture also produced 21.0 microg ml(-1) of growth hormone indole acetic acid (IAA) in the presence of 500 microg ml(-1) of tryptophan. The IAA production was stimulated at lower concentrations of butachlor, whereas higher concentrations above 0.8 mmol l(-1) were found inhibitory.


CONCLUSIONS
The isolate JS-1 characterized as Stenotrophomonas acidaminiphila was capable of utilizing butachlor as sole source of carbon and energy. Besides being an efficient butachlor degrader, it substantially produces IAA.


CONCLUSIONS
The bacterial strain JS-1 has a potential for butachlor remediation with a distinctive auxiliary attribute of plant growth stimulation.
Dwivedi
S
S
Al-Jeraisy Chair for DNA Research, College of Science, King Saud University, Riyadh, Saudi Arabia.
Singh
B R
BR
Al-Khedhairy
A A
AA
Alarifi
S
S
Musarrat
J
J
D000083:Acetanilides / Q000378:metabolism*; D001711:Biotransformation; D002851:Chromatography, High Pressure Liquid; D016000:Cluster Analysis; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D006207:Half-Life; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D020588:Stenotrophomonas / Q000302:isolation & purification* / Q000378:metabolism*; D013997:Time Factors; D014364:Tryptophan / Q000378:metabolism
D000083:Acetanilides; D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D012336:RNA, Ribosomal, 16S; C030737:indoleacetic acid; D014364:Tryptophan; C054409:butachlor