Abstract

Luvuyo Ntsaluba, Mayowa Agunbiade, Leonard Mabinya* and Anthony Okoh

A bioflocculant-producing bacterium isolated from river water was identified as Methylobacterium sp. Obi by 16S ribosomal ribonucleic acid (rRNA) gene sequencing. The nucleotide sequence was deposited in the Genbank with accession number HQ537130. The bioflocculant secreted by the isolate showed a peak flocculating activity of 72% in 1 g/L kaolin suspension supplemented with CaCl2. The bioflocculant yield was maximal when glucose and peptone were used as carbon and nitrogen sources respectively, at an optimum pH of 7. Calcium was the most effective cation in stimulating bioflocculating activity. Chemical analyses of the purified bioflocculant revealed it to be a polysaccharide.