Effect of Various Carbon and Nitrogen Sources on Decolorization of Textile Dyes by Pseudomonas taiwanensis Strain TNZ3

Abstract

The co-substrate is a crucial component in the bio-decolorization process that helps bacteria to grow and carry out their fundamental functions. Different types of textile dyes with diverse chemical structures are frequently employed in the textile industry, and the most of them are resistant to biodegradation because of their xenobiotic nature. Due to the low carbon content of textile dyes, particularly of azo dyes, co-metabolic conditions are required for decolorization process. Hence, the current study was aimed to determine which striking carbon and nitrogen sources are preferred for generating co-metabolic conditions to decolorize the following dyes: Disperse Yellow-3, Malachite Green, Basic Red-18, and Reactive Blue-4. Different carbon and nitrogen sources were used to isolate, screen, and evaluate different bacterial strains for dye degradation. A potential bacterial strain Pseudomonas taiwanensis strain TNZ3 was identified based on 16s rDNA sequence and selected for further study. It was found that the presence of yeast, peptone, NH4Cl, sucrose, glucose, fructose, maltose, galactose, lactose, and starch in dye contaminated media effectively enhanced azo dye degradation rate by Pseudomonas taiwanensis strain TNZ3. In the medium inoculated with Pseudomonas taiwanensis strain TNZ3, sucrose and yeast with peptone extracts induced the greatest decolorization among diverse carbon and nitrogen sources. In all dyes, the maximum decolorization occurs at 1.5% yeast extract supplementation. The results made it abundantly clear that various carbon and nitrogen sources used as co-substrates played effective role on dye decolorization process.