title: Role of Ni-tolerant Bacillus spp. and Althea rosea L. in the phytoremediation of Ni-contaminated soils.
abstract: In our current study, four nickel-tolerant (Ni-tolerant) bacterial species viz, Bacillus thuringiensis 002, Bacillus fortis 162, Bacillus subtilis 174, and Bacillus farraginis 354, were screened using Ni-contaminated media. The screened microbes exhibited positive results for synthesis of indole acetic acid (IAA), siderophore production, and phosphate solubilization. The effects of these screened microbes on Ni mobility in the soil, root elongation, plant biomass, and Ni uptake in Althea rosea plants grown in Ni-contaminated soil (200 mg Ni kg-1) were evaluated. Significantly higher value for water-extractable Ni (38 mg kg-1) was observed in case of Ni-amended soils inoculated with B. subtilis 174. Similarly, B. thuringiensis 002, B. fortis 162, and B. subtilis 174 significantly enhanced growth and Ni uptake in A. rosea. The Ni uptake in the shoots and roots of B. subtilis 174-inoculated plants enhanced up to 1.7 and 1.6-fold, respectively, as compared to that in the un-inoculated control. Bacterial inoculation also significantly improved the root and shoot biomass of treated plants. The current study presents a novel approach for bacteria-assisted phytoremediation of Ni-contaminated areas.
authors.affiliation: a College of Earth and Environmental Sciences, University of the Punjab , Lahore , Pakistan.
authors.forename: Waheed Ullah
authors.initials: WU
authors.lastname: Khan
authors.affiliation: b Resident Officer II, University of the Punjab , Lahore , Pakistan.
authors.forename: Nasim Ahmad
authors.initials: NA
authors.lastname: Yasin
authors.affiliation: a College of Earth and Environmental Sciences, University of the Punjab , Lahore , Pakistan.
authors.forename: Sajid Rashid
authors.initials: SR
authors.lastname: Ahmad
authors.affiliation: c Department of Botany , University of Sargodha , Sargodha , Pakistan.
authors.forename: Aamir
authors.initials: A
authors.lastname: Ali
authors.affiliation: d Department of Botany , University of the Punjab , Lahore , Pakistan.
authors.forename: Shakil
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: e Institute of Agricultural Sciences, University of the Punjab , Lahore , Pakistan.
authors.forename: Aqeel
authors.initials: A
authors.lastname: Ahmad
mesh_terms: D031583:Althaea / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology; D001407:Bacillus / Q000378:metabolism*; D001673:Biodegradation, Environmental; D009532:Nickel / Q000378:metabolism*; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D009532:Nickel
keywords: Althea rosea; bacillus; phytoremediation