Characterization of a bioflocculant produced from the consortium of three marine bacteria of the genera Cobetia and Bacillus and its application for wastewater treatment

Abstract

In this study, we purified and characterized bioflocculant from a mixed culture of three marine bacteria (Cobetia sp. OAUIFE, Bacillus sp. MAYA, and Bacillus sp. Gilbert with accession number JF799092, JF799093, and HQ537128, respectively) isolated from the sediment sample of Algoa Bay South Africa. The bioflocculant from the consortium showed high flocculation of river water, brewery wastewater, and dairy wastewater, with resultant flocculating activities of 96.4%, 93.7%, and 82.2%, respectively. The applicability of the bioflocculant for removing turbidity and reducing chemical oxygen demand (COD) from these real wastewaters was excellent. The bioflocculant turbidity removal efficiency for brewery wastewater was 92%, while its COD reduction efficiency for dairy wastewater was 99%. A scanning electron microscopy (SEM) image of the purified bioflocculant revealed an amorphous morphology, while Fourier transform infra-red (FTIR) analysis also revealed the presence of amino, hydroxyl, and carboxyl functional groups among others, which could be responsible for the high-flocculating activity of the bioflocculant. This environmental-friendly bioflocculant holds promise for application in the field of biotechnology.