Investigating the Bioflocculant Production Potential of Microorganisms Isolated From Earthen Pond Sludge

Abstract

Background: Bioflocculants are biodegradable polymers produced by microorganisms and have gained applications in aggregating dissolved and suspended substances in water. This study aimed to screen, isolate and identify microorganisms from earthen pond sludge for flocculant production. Materials and Methods: Samples were collected from earthen pond sludge in Lapai Gwari in Bosso Local Government Area of Minna, Nigeria located at longitude 6.5052°E and latitude 9.5246°N, and screened for microorganisms with bioflocculating ability using kaolin suspension and selective medium containing (per liter) NaCl 0.1 g, MgSO47H2O 0.2 g, K2HPO4 5 g, agar 5.5 g, yeast extract 0.5 g, urea 0.5 g, KH2PO4 2 g, and glucose 10 g for bacteria, and MgSO47H2O 0.2 g, K2HPO4 5 g, agar 5.5 g, yeast extract 0.5 g, urea 0.5 g, KH2PO4 2 g, glucose 10 g for fungi. The lyophilized bioflocculant produced by the bacterium was characterized using thermogravimetric property analysis (TGA), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) Results and Conclusion: Of the twelve (12) microorganisms isolated, Prestia megaterium (accession number ON184360) gave the highest potential (30 %) for flocculant production. Tyrosine-protein kinase gene was detected to be responsible for the bioflocculant production. A total of 10.67 g of bioflocculant was produced from 500 mL of the medium. The TGA, FTIR spectra and scanning electron micrograph exhibited typical characteristics of flocculant. The findings of this investigation indicated that Priestia megaterium isolated from earthen pond sludge is a suitable substitute for flocculant production.