Production of Bioflocculants from Bacillus subtilis-2162 and Determination of Its Flocculating Activity on Heavy Metal Chromium

Abstract

The bioflocculant production potential of Bacillus subtilis-2162 was evaluated using standard methods. The bacteria produced an extracellular bioflocculant. Culture conditions for optimal production of the bioflocculants include: glucose and sucrose as carbon sources; multiple + 2 nitrogen sources including: ammonium sulfate and yeast extract; Ca⁺² as sole cation source; and initial medium of pH 7. Characterization of the pure bioflocculants revealed that it is thermostable. Hydroxyl, carboxyl and amino groups were also present in the bioflocculant compound as functional groups. The flocculating activity was calculated based on absorbance at a wavelength of 550 nm. Bioflocculant produced in this study is capable of removing heavy metal chromium from synthetic solution effectively. The findings of this study suggest that B. subtilis-2162 holds immense promise as a source of important bioflocculant that could serve as an alternative to synthetic flocculants.

Keywords: Bioflocculant, Bacillus subtilis-2162, hexavalent chromium (Cr⁺⁶), exopolysaccharide