| Summary: | Excess doses of trace element contamination make conventional water treatment methods less effective and more expensive, where in alternative biotechnological applications open up new opportunities with their reduced cost and lesser impacts to the environment. In the present investigation, effectiveness of aquatic macrophyte Eichhornia crassipes was tested for the removal of copper in laboratory conditions. Water samples were collected from macrophytes natural habitat and water tubs used for growing E. crassipes and analysed along with plant tissues for Cu content. The work also characterized the associated microbiota of the rhizosphere system of the E. crassipes as well as the wetland system of its occurrence. Copper concentration of the wetland water samples ranged from 0.009 to 0.03ppm. Six bacterial genera (Acinetobacter, Alcaligenes, Bacillus, Kurthia, Listeria and Chromobacterium) were represented in rhizosphere of E.crassipes and 4 bacterial genera (Acinetobacter, Bacillus, Listeria and Chromobacterium) were recorded in wetland water samples. Copper resistance studies of the bacterial isolates showed that out of 26 isolates from rhizosphere and 19 strains from water samples,12 of them showed low resistance (< 100 µg/ml) and 5 isolates showed high resistance to copper at concentration of 400-500 µg/ml. Two high copper-resistant bacteria from the rhizosphere were selected for 16S rDNA analysis. The results found that one isolate showed 99% similarity with Bacillus altitudinis strain- Y118 16S ribosomal RNA gene, partial sequence (Accession No: JX134625.1) and the other showed 99% similarity with Bacillus altitudinis strain SH164 16S ribosomal RNA gene, partial sequence (Accession No: KC172059.1). Results of copper removal revealed high removal (>80%) of copper during 15 days experiment. Copper accumulation was found to be high in the root followed by leaf and petiole. Results of the present study concluded that E. crassipes is an efficient plant for the removal of copper.
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