title: Improvement of methyl orange dye biotreatment by a novel isolated strain, Aeromonas veronii GRI, by SPB1 biosurfactant addition.
abstract: Aeromonas veronii GRI (KF964486), isolated from acclimated textile effluent after selective enrichment on azo dye, was assessed for methyl orange biodegradation potency. Results suggested the potential of this bacterium for use in effective treatment of azo-dye-contaminated wastewaters under static conditions at neutral and alkaline pH value, characteristic of typical textile effluents. The strain could tolerate higher doses of dyes as it was able to decolorize up to 1000 mg/l. When used as microbial surfactant to enhance methyl orange biodecolorization, Bacillus subtilis SPB1-derived lipopeptide accelerated the decolorization rate and maximized slightly the decolorization efficiency at an optimal concentration of about 0.025%. In order to enhance the process efficiency, a Taguchi design was conducted. Phytotoxicity bioassay using sesame and radish seeds were carried out to assess the biotreatment effectiveness. The bacterium was able to effectively decolorize the azo dye when inoculated with an initial optical density of about 0.5 with 0.25% sucrose, 0.125% yeast extract, 0.01% SPB1 biosurfactant, and when conducting an agitation phase of about 24 h after static incubation. Germination potency showed an increase toward the nonoptimized conditions indicating an improvement of the biotreatment. When comparing with synthetic surfactants, a drastic decrease and an inhibition of orange methyl decolorization were observed in the presence of CTAB and SDS. The nonionic surfactant Tween 80 had a positive effect on methyl orange biodecolorization. Also, studies ensured that methyl orange removal by this strain could be due to endocellular enzymatic activities. To conclude, the addition of SPB1 bioemulsifier reduced energy costs by reducing effective decolorization period, biosurfactant stimulated bacterial decolorization method may provide highly efficient, inexpensive, and time-saving procedure in treatment of textile effluents.
authors.affiliation: Unité Enzymes et Bioconversion, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, ENIS, BP W 3038, Sfax, Tunisia. inesmnif2011@gmail.com.|Institut Supérieur de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisia. inesmnif2011@gmail.com.|Faculté des Sciences de Gabes, Gabes, Tunisie. inesmnif2011@gmail.com.
authors.forename: Inès
authors.initials: I
authors.lastname: Mnif
authors.affiliation: Unité Enzymes et Bioconversion, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, ENIS, BP W 3038, Sfax, Tunisia.|Institut d'Oliviers, Laboratoire d'Amélioration de la Productivité de l'Olivier et la Qualité du Produit, Sfax, Tunisie.
authors.forename: Sameh
authors.initials: S
authors.lastname: Maktouf
authors.affiliation: Unité Enzymes et Bioconversion, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, ENIS, BP W 3038, Sfax, Tunisia.|Institut Supérieur de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisia.
authors.forename: Raouia
authors.initials: R
authors.lastname: Fendri
authors.affiliation: Institut Supérieur de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisia.|Laboratoire des Micro-organismes et Biomolécules, Centre de Biotechnologie de Sfax, Sfax, Tunisie.
authors.forename: Mouna
authors.initials: M
authors.lastname: Kriaa
authors.affiliation: Unité Enzymes et Bioconversion, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, ENIS, BP W 3038, Sfax, Tunisia.
authors.forename: Semia
authors.initials: S
authors.lastname: Ellouze
authors.affiliation: Unité Enzymes et Bioconversion, Ecole Nationale d'Ingénieurs de Sfax, Université de Sfax, ENIS, BP W 3038, Sfax, Tunisia.|Institut Supérieur de Biotechnologie de Sfax, Université de Sfax, Sfax, Tunisia.
authors.forename: Dhouha
authors.initials: D
authors.lastname: Ghribi
mesh_terms: D000333:Aeromonas / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001391:Azo Compounds / Q000378:metabolism*; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000378:metabolism*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D011136:Polysorbates / Q000032:analysis; D013501:Surface-Active Agents / Q000032:analysis; D013784:Textiles; D062065:Wastewater / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D011136:Polysorbates; D013501:Surface-Active Agents; D062065:Wastewater; D014874:Water Pollutants, Chemical; C100258:methyl orange
keywords: Aeromonas sp.; Biodecolorization; Biosurfactants; Methyl orange; Phytotoxicity; Taguchi