title: Tolerance and bioaccumulation of U(VI) by Bacillus mojavensis and its solid phase preconcentration by Bacillus mojavensis immobilized multiwalled carbon nanotube.
abstract: In this study, uranium(VI) tolerance and bioaccumulation were investigated by using thermo -tolerant Bacillus mojavensis. The level of U(VI) was measured by UV-VIS spectrophotometry. The minimum inhibition concentration (MIC) value of U(VI) was experimented. Bacterial growth was not affected in the presence of 1.0 and 2.5 mg/L U(VI) at 36 h and the growth was partially affected in the presence of 5 mg/L U(VI) at 24 h. What was obtained from this study is that there was diversity in the various periods of the growth phases of metal bioaccumulation capacity, which was shown by B. mojavensis. The maximum bioaccumulation capacities were found to be 12.8, 22.7, and 48.2 mg/g dried bacteria, at 24th hours at concentration of 1.0, 2.5 and 5 mg/L U(VI), respectively. In addition to these, U(VI) has been preconcentrated on B. mojavensis immobilized MWCNT. Several factors such as pH, flow rate of solution, amount of biosorbent and support materials, eluent type, concentration and volume, the matrix interference effect on retention have been studied, and extraction conditions were optimized. Preconcentration factor was achieved as 60. Under the optimized conditions, the limit of detection (LOD) and quantification (LOQ) were calculated as 0.74 and 2.47 μg/L. The biosorption capacity of immobilized B. mojavensis was calculated for U(VI) as 25.8 mg/g. The results demonstrated that the immobilized biosorbent column could be reused at least 30 cycles of biosorption and desorption with the higher than 95% recovery. FT-IR and SEM analysis were performed to understand the surface properties of B. mojavensis.
authors.affiliation: Department of Biology, Faculty of Art and Science, Siirt University, 56100 Siirt, Turkey. Electronic address: sadin77@hotmail.com.
authors.forename: Sadin
authors.initials: S
authors.lastname: Özdemir
authors.affiliation: Department of Biology, Faculty of Art and Science, Siirt University, 56100 Siirt, Turkey.
authors.forename: M Kadir
authors.initials: MK
authors.lastname: Oduncu
authors.affiliation: Health Services Vocational High School, Medical Marketing and Promotion Programme, Mardin Artuklu University, 47200 Mardin, Turkey.
authors.forename: Ersin
authors.initials: E
authors.lastname: Kilinc
authors.affiliation: Department of Chemistry, Faculty of Sciences, Erciyes University, TR-38039 Kayseri, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Soylak
mesh_terms: D001407:Bacillus / Q000378:metabolism*; D019149:Bioreactors; D002412:Cations; D006801:Humans; D037742:Nanotubes, Carbon; D011868:Radioisotopes / Q000378:metabolism*; D062611:Solid Waste; D017550:Spectroscopy, Fourier Transform Infrared; D014501:Uranium / Q000378:metabolism*
chemical_list: D002412:Cations; D037742:Nanotubes, Carbon; D011868:Radioisotopes; D062611:Solid Waste; D014501:Uranium
keywords: Bacillus mojavensis; Resistance and bioaccumulation; Solid phase extraction preconcentration; U(VI)