title: Removal of triphenylmethane dyes by bacterial consortium.
abstract: A new consortium of four bacterial isolates (Agrobacterium radiobacter; Bacillus spp.; Sphingomonas paucimobilis, and Aeromonas hydrophila)-(CM-4) was used to degrade and to decolorize triphenylmethane dyes. All bacteria were isolated from activated sludge extracted from a wastewater treatment station of a dyeing industry plant. Individual bacterial isolates exhibited a remarkable color-removal capability against crystal violet (50 mg/L) and malachite green (50 mg/L) dyes within 24 h. Interestingly, the microbial consortium CM-4 shows a high decolorizing percentage for crystal violet and malachite green, respectively, 91% and 99% within 2 h. The rate of chemical oxygen demand (COD) removal increases after 24 h, reaching 61.5% and 84.2% for crystal violet and malachite green, respectively. UV-Visible absorption spectra, FTIR analysis and the inspection of bacterial cells growth indicated that color removal by the CM-4 was due to biodegradation. Evaluation of mutagenicity by using Salmonella typhimurium test strains, TA98 and TA100 studies revealed that the degradation of crystal violet and malachite green by CM-4 did not lead to mutagenic products. Altogether, these results demonstrated the usefulness of the bacterial consortium in the treatment of the textile dyes.
authors.affiliation: Laboratory of Analysis, Treatment, Valorisation and Environmental Pollution and Products, Faculty of Pharmacy, University of Monastir, Monastir Avicenne Street, Monastir 5000, Tunisia. jihane_cheriaa@yahoo.fr
authors.forename: Jihane
authors.initials: J
authors.lastname: Cheriaa
authors.forename: Monia
authors.initials: M
authors.lastname: Khaireddine
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Rouabhia
authors.forename: Amina
authors.initials: A
authors.lastname: Bakhrouf
mesh_terms: D016980:Aeromonas hydrophila / Q000378:metabolism; D060054:Agrobacterium / Q000378:metabolism; D001407:Bacillus / Q000378:metabolism; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000378:metabolism*; D005840:Gentian Violet / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D009152:Mutagenicity Tests; D012394:Rosaniline Dyes / Q000378:metabolism; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D020578:Sphingomonas / Q000378:metabolism; D014320:Triphenylmethyl Compounds / Q000378:metabolism*
chemical_list: D004396:Coloring Agents; D007220:Industrial Waste; D012394:Rosaniline Dyes; D014320:Triphenylmethyl Compounds; C005095:malachite green; C046945:triphenylmethane; D005840:Gentian Violet