Efficiency of Bacterial Strains in Decolorization of Hazardous Dyes under Sustainability Conditions

Synthetic dyes are frequently used as additive compounds in different industries. The dramatic increase of toxic dyes and their strong durability and stability in aquatic environments lead to rising severity of both the environment and human health. The current study shows the efficiency of bacteria as biological agents in decolorizing some hazardous dyes, without energy supply and chemical substance uses. In this study, the potential of two identified proteus strains (P. strain C and P. strain Y) isolated from the main opened wastewater of Soran City-Iraq was assessed for decolorization of Methylene blue (MB) and Methyl orange (MO). The bacterial strains were separately and together as a consortium tested at different concentrations of the selected dyes (10, 30, 50 and 100 mg/l). After 48 hours of incubation, the decolorization efficiency of the two isolates was significantly observed with respect to the concentrations, and this efficiency lowered with increasing concentration. The decolorization efficiency for MB dye ranged from 67% to 75% by P. strain C, and from 73% to 79% by P. strain Y. Whereas, the efficiency of the mixed culture of the two isolated bacteria (consortium) ranged in 79-88%. MO was more easily degradable than MB, and the efficiency was >90% by individual experiment, and >96% by consortium. In conclusion, the two newly isolated proteus strains were confirmed as promising biological agents for degradation of MB and MO. Therefore, the isolates can be proposed as biological agents for bioremediation under environmental sustainability.