Screening and characterization of bioflocculant-producing bacteria isolated from domestic waste water in Bowen University, Iwo, Osun State, Nigeria

Abstract

Bioflocculants are biodegradable polymers produced by microorganisms. Bioflocculant has some advantages over synthetic flocculant. They are safe, harmlessness to humans and environment with strong effect. However, its production and application is still at minimal level. This study aimed at screening for bioflocculant-producing bacteria isolated from eatery waste water in Bowen University, Iwo, Osun State.The flocculating activity of the isolated organism was investigated using 5g/L kaolin suspension to measure the flocculating activity at optical density (OD) of 550nm. A total of twentyeight (28) bacteria strains were isolated from four (4) different domestic waste water samples and their bioflocculant activities were determined. Five isolates with high percentage flocculating activity were obtained as follow; Y4 (67%), P3 (61%), B8 (60%), K8 (55%)and K4 (52%). The isolates were characterized using morphological and molecular methods and they were identified as Bacillus licheniformis (B8, K4 and K8), Bacillus thuringensis (Y4) and Bacillus cereus (P3). The 16S rRNA sequence analysis revealed the isolates as related to the genus Bacillus and the nucleotide sequence were deposited in GenBank as Bacillus species with the accession numbers KY352342 (B8), KY352343 (P3), and KY352344 (Y4). Accession numbers for isolates K4 and K8 were not determined.

Keywords: Waste water, Bioflocculant production, Bioflocculating activity, Bacteria, Bacillus species