Decolorization of the textile dyes by newly isolated bacterial strains

• Published in: Journal of biotechnology 2003-02, Vol.101 (1), p.57-68
• Main Authors: Chen, Kuo-Cheng, Wu, Jane-Yii, Liou, Dar-Jen, Hwang, Sz-Chwun John
• Format: Article
• Language: English
• Subjects: Aeromonas hydrophila; Aeromonas hydrophila - classification; Aeromonas hydrophila - growth & development; Aeromonas hydrophila - isolation & purification; Aeromonas hydrophila - metabolism; Anthraquinone dyes; Anthraquinones - metabolism; Azo Compounds - metabolism; Azo dyes; Bacteria, Anaerobic - classification; Bacteria, Anaerobic - growth & development; Bacteria, Anaerobic - isolation & purification; Bacteria, Anaerobic - metabolism; Biodegradation, Environmental; Biological and medical sciences; Cells, Cultured; Coculture Techniques; Color; Coloring Agents - metabolism; Fundamental and applied biological sciences. Psychology; Glucose - metabolism; Hydrogen-Ion Concentration; Hydrolysis; Indigo dyes; Indoles - metabolism; Industrial Waste - prevention & control; Microbial decolorization; Nitrogen - metabolism; Sewage - microbiology; Species Specificity; Taiwan; Temperature; Textiles; Waste Disposal, Fluid - methods; Water Pollutants, Chemical - metabolism; Water Purification - methods
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/S0168-1656(02)00303-6

Six bacterial strains with the capability of degrading textile dyes were isolated from sludge samples and mud lakes. Aeromonas hydrophila was selected and identified because it exhibited the greatest color removal from various dyes. Although A. hydrophila displayed good growth in aerobic or agitation culture (AGI culture), color removal was the best in anoxic or anaerobic culture (ANA culture). For color removal, the most suitable pH and temperature were pH 5.5–10.0 and 20–35 °C under anoxic culture (ANO culture). More than 90% of RED RBN was reduced in color within 8 days at a dye concentration of 3000 mg l −1. This strain could also decolorize the media containing a mixture of dyes within 2 days of incubation. Nitrogen sources such as yeast extract or peptone could enhance strongly the decolorization efficiency. In contrast to a nitrogen source, glucose inhibited decolorization activity because the consumed glucose was converted to organic acids that might decrease the pH of the culture medium, thus inhibiting the cell growth and decolorization activity. Decolorization appeared to proceed primarily by biological degradation.