Congo red dye removal by β-glucans producing bacteria strains

Abstract

Dye pollutants from textile processing are concerning. The textile industry consumes large water quantity and discharge high volume of dye-containing wastewater. Dye pollutants that are discharged to waterways are often difficult to be degraded due to their aromatic and heterocyclic compounds properties. In this study, the capabilities of β-glucans - producing bacteria strains to remove Congo Red dye from water solution were investigated. Two β-glucans producing bacteria strains, Agrobacterium sp. ATCC 31749 and newly isolated strain, PI-18 were used in this study. Agrobacterium sp. ATCC 31749 is known to produce β-1-3 linear glucans, while the β-glucan produced by PI-18 strain is yet to be determined. These bacteria strains were grown in flasks containing production medium supplemented with 0.004% (w/v) and 0.03% (w/v) of Congo Red dye. Concentrations of the dye were monitored via spectrophotometer measurement of the supernatant daily. At lower initial concentration of 0.004% w/v of Congo Red, both β-glucans-producing strains showed identical dye removing capability, in which approximately 70% of the dye were removed from the solution after four days of incubation. At higher initial concentration of Congo Red (0.03% w/v), PI-18 strain outperformed Agrobacterium sp. ATCC 31749 strain, with after three days of incubation, almost 95% of the dye removed from solution while Agrobacterium sp. ATCC 31749 only capable removing half of the amount. The results suggest that β-glucans-producing strains have the potential to be utilized for application in bioremediation of wastewater treatment in the textile industry.