Screening and Characterization of Bioflocculants Producing Bacteria Isolated from Ponds in Kano Metropolis

Bioflocculants are extracellular polymers produced by microorganisms, these polymers are capable of forming stable aggregates of flocs. Compared with high molecular-weight synthetic flocculants, which are known to be harmful to the environment and human health, bioflocculants are biodegradable and non-toxic. The study screened and characterized bacteria isolated from ponds for efficient bioflocculants production potentials. Water samples were collected from ponds within Kano metropolis. Bacteria were isolated from the samples and screened for bioflocculants production by growing them on Yeast extracts Peptone Glycerol agar (YPG agar). Bioflocculants were produced by growing isolates in an enrichment broth medium. A Modified Kaolin clay suspension method was used for flocculating activity assay. The isolates were identified using biochemical test while two isolates were further identified using molecular technique. The screening identified four isolates as flocculants producing strains, their flocculation activity assay shows significant difference (p value <0.05), Escherichia furgusonii has the highest flocculating activity (79.31%), while Bacillus subtilis produces the least (68.20%). The consortia of two combination isolates show flocculating activity ranging 58.42% to 69.02% by Escherichia furgusonii and Pseudomonas aeruginosa, and Bacillus subtilis and Pseudomonas aeruginosa respectively. Consortiums of three combination isolates shows flocculating activity of 49.85% to 57.55%, by Bacillus cereus, Escherichia furgusonii and Pseudomonas aeruginosa, and Bacillus cereus, Escherichia furgusonii and Bacillus subtilis respectively. The study revealed that these isolates can produce bioflocculants with varying flocculating activity. It is therefore concluded that the isolates can be used for bioflocculants production due to their flocculants production potentials.