Bio-decolourization of Reactive Blue EFAF using halotolerant Exiguobacterium profundumstrain CMR2 isolated from salt pan.

Abstract Two halotolerant bacteria isolated from water samples of saltpan located at Ramanathapuram district, Tamil Nadu and tested their dye decolourization efficiency against four textile dyes. Of the tested strains, strain CMR2 showed maximum decolourization (98%) for Reactive Blue EFAF within 24 h. Further, strain CMR2 was identified as Exiguobacterium profundum using 16 s rDNA sequence analysis. It is noteworthy that the isolated halotolerant bacteria possess the ability to decolorize the reactive blue EFAF dye even in wide range of NaCl concentrations (5–30%) and pH (5–10). Decolourization efficiency was significantly increased upto 85% and 92% when the medium supplemented with starch and peptone as carbon and nitrogen source. Findings from UV–vis, FTIR spectral analysis before and after decolourization confirmed that the dye was decolourized completely via biodegradation. The present study suggest that Exiguobacterium profundum can be used as an effective candidate for the decolourization of waste water containing reactive blue EFAF. Highlights • Halotolerant bacteria were isolate from salt pan located near Ramanathapuram. • Isolated strains tested for its efficiency against four different textile dyes. • Efficient decolorizing strain was selected and identified as E. profundum. • Maximum decolorizing efficiency of 94% at 18h observed in 200 mg/l conc. • The end product of E. profundum analyzed using FTIR to confirms the decolorization. [ABSTRACT FROM AUTHOR]