Decolorization of methyl red using <i>Bacillus thuringiensis</i> RI16 strain: Enhanced bacterial treatment by SPB1 biosurfactant addition

Abstract In this work, we evaluate the ability of a novel isolated bacteria identified as Bacillus thuringiensis RI16 (KM111604) to decolorize methyl red. Results showed its efficiency for treatment azo-dye-contaminated wastewaters under static conditions at pH values ranging from 7 9. The could tolerate higher doses dyes it was able up 1000 mg/L. For better red decolorization, potential use subtilis SPB1-derived lipopeptide biosurfactant. study accelerate decolorization rate and slightly maximized an optimal concentration 0.025%. Compared with synthetic surfactants, bacterial surfactant more efficient observe drastic decrease inhibition by cetyl trimethylammonium bromide (CTAB) sodium dodecyl sulfate (SDS) additions. Also, studies ensured that removal strain be due extracellular enzymatic activities. SPB1 biosurfactant improve enzyme activities and/or synthesis diffusion.