title: Characterization of a salt resistant bacterial strain Proteus sp. NA6 capable of decolorizing reactive dyes in presence of multi-metal stress.
abstract: Microbial biotechnologies for the decolorization of textile wastewaters have attracted worldwide attention because of their economic suitability and easiness in handling. However, the presence of high amounts of salts and metal ions in textile wastewaters adversely affects the decolorization efficiency of the microbial bioresources. In this regard, the present study was conducted to isolate salt tolerant bacterial strains which might have the potential to decolorize azo dyes even in the presence of multi-metal ion mixtures. Out of the tested 48 bacteria that were isolated from an effluent drain, the strain NA6 was found relatively more efficient in decolorizing the reactive yellow-2 (RY2) dye in the presence of 50 g L(-1) NaCl. Based on the similarity of its 16S rRNA gene sequence and its position in a phylogenetic tree, this strain was designated as Proteus sp. NA6. The strain NA6 showed efficient decolorization (>90 %) of RY2 at pH 7.5 in the presence of 50 g L(-1) NaCl under static incubation at 30 °C. This strain also had the potential to efficiently decolorize other structurally related azo dyes in the presence of 50 g L(-1) NaCl. Moreover, Proteus sp. NA6 was found to resist the presence of different metal ions (Co(+2), Cr(+6), Zn(+2), Pb(+2), Cu(+2), Cd(+2)) and was capable of decolorizing reactive dyes in the presence of different levels of the mixtures of these metal ions along with 50 g L(-1) NaCl. Based on the findings of this study, it can be suggested that Proteus sp. NA6 might serve as a potential bioresource for the biotechnologies involving bioremediation of textile wastewaters containing the metal ions and salts.
authors.affiliation: Department of Environmental Sciences & Engineering, Government College University, Allama Iqbal Road, Faisalabad, Pakistan.
authors.forename: Naila
authors.initials: N
authors.lastname: Abbas
authors.affiliation: Department of Environmental Sciences & Engineering, Government College University, Allama Iqbal Road, Faisalabad, Pakistan. sabirghani@gmail.com.|UCD School of Biomolecular and Biomedical Sciences, University College Dublin, Belfield, Dublin 4, Ireland. sabirghani@gmail.com.
authors.forename: Sabir
authors.initials: S
authors.lastname: Hussain
authors.affiliation: Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan.
authors.forename: Farrukh
authors.initials: F
authors.lastname: Azeem
authors.affiliation: Department of Environmental Sciences & Engineering, Government College University, Allama Iqbal Road, Faisalabad, Pakistan.
authors.forename: Tanvir
authors.initials: T
authors.lastname: Shahzad
authors.affiliation: Department of Statistics, Government College University, Faisalabad, Pakistan.
authors.forename: Sajjad Haider
authors.initials: SH
authors.lastname: Bhatti
authors.affiliation: Department of Soil Science, Muhammad Nawaz Sharif University of Agriculture, Multan, Pakistan.|Environmental Microbiology, Soil Science Division, Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad, 38000, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Imran
authors.affiliation: Department of Environmental Sciences, PMAS Arid Agriculture University, Rawalpindi, Pakistan.
authors.forename: Zulfiqar
authors.initials: Z
authors.lastname: Ahmad
authors.affiliation: Department of Environmental Sciences & Engineering, Government College University, Allama Iqbal Road, Faisalabad, Pakistan.
authors.forename: Zahid
authors.initials: Z
authors.lastname: Maqbool
authors.affiliation: Department of Plant Pathology, Faculty of Agricultural Sciences and Technology, Bahauddin Zakaria University, Multan, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Abid
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000737:chemistry*; D007220:Industrial Waste / Q000032:analysis; D019216:Metals, Heavy / Q000737:chemistry*; D010802:Phylogeny; D011511:Proteus / Q000235:genetics / Q000302:isolation & purification*; D017423:Sequence Analysis, RNA; D012965:Sodium Chloride / Q000737:chemistry*; D013783:Textile Industry / Q000379:methods; D062065:Wastewater / Q000382:microbiology
chemical_list: D004396:Coloring Agents; D007220:Industrial Waste; D019216:Metals, Heavy; D012965:Sodium Chloride; D062065:Wastewater
keywords: Bioremediation; Decolorization; Proteus sp. NA6; Reactive dyes; Salt and metal resistance