Biodegradation of textile dye Rhodamine-B by Brevundimonas diminuta and screening of their breakdown metabolites

The carcinogenic Rhodamine-B dye is recalcitrant which could cause serious hazards to human beings. Degradation with the application of unique bacterial strain is a sustainable technique. The bioremediation technique showed great potential to degrade a variety of recalcitrant pollutants like dyes. In this study, Brevundimonas diminuta, was selected for the breakdown of toxic textile dye Rhodamine-B. This bacterium showed 90–95% of degradation at the optimum conditions like 10 mg L−1 of concentration of dye, pH 7 and temperature of 30 °C. Further UV–Visible spectrophotometry, FT-IR spectral scan, GC-MS analysis depicted the breakdown products like Methyl 18-fluoro-octadec-9-enoate, Methyl 18-fluoro-octadec-9-enoate and d-Homo-24-nor-17-oxachola-20,22-diene-3,16-dione,7-(acetyloxy)-1, 23 tri-epoxy-4,4,8-trimethyl. The degradation was confirmed by the changes in the functional groups, change in molecular weight and charge to-mass ratio. These results suggested that this strain is a deserving organism for the degradation of dye compounds. •The novel bacterial strain Brevundimonas diminuta was identified and applied for the degradation of Rhodamine-B dye.•During degradation, several parameter studies like pH, temperature, concentration, nitrogen source and carbon source were evaluated using UV–Visible spectroscopy.•In all the studies, Brevundimonas diminuta proved with high degradation efficiency.•The degraded metabolite was found to be Phenol, 2,4-bis(1,1-dimethylethyl).