ABSTRACT
Dyes have a long history of serving as industrial colorants. They are mainly utilized in the food, textile, and pharmaceutical industries to give the finished products an excellent appearance. While natural dyes are biodegradable and constitute a lesser hazard to the environment, synthetic dyes, especially, those belonging to the azo family are recalcitrant. As the contamination of dye in the environment increases due to increase in demand, accumulation of dye molecules with their hazard is gradually becoming a global menace. Remediation of dyes include the use of conventional physicochemical methods, physical treatments, and bioremediation. Bioremediation involves the use of microorganisms or their products. Bioremediation is preferred because it is cost-effective and eco-friendly. In this chapter, the nature and structure of dyes were discussed with emphasis on dyes bioremediation. While researchers have observed a dye degrading property from group of microorganisms like fungi, bacteria, actinomycetes, and algae, anaerobic bacterial degradation of dye molecules is faster and more efficient. Although the application of bacterial species and other microorganisms to degrade dye molecules has yielded excellent results in laboratory and controlled studies, there are limitations posed by the nature of the environment, type of organism involved, and the type of dye molecule to be degraded. The most important remedy to this challenge will be to improve microbial strains for better dye degrading abilities.
