Characterization Of Bioflocculant-producing Bacteria Isolated in Vietnam for Harvesting of Indigenous Microalgae

Le Thi Anh Tu


Bioflocculation producing bacteria isolated from soil and sediment in Da Lat City, Lam Dong Province, Vietnam, were characterized. Four bacterial strains that had high flocculation activity were Flavobacterium granuli CL, Hydrogenophaga pseudoflava DA, Alcaligenes cupidus PT2, Bacillus mucilaginosus PT3, with the flocculation efficiency of 91.37%, 83.12%, 76.92%, and 75.81%, respectively at 22°C, pH 10, the initial algae concentration (optical density at 690nm) of 1.25, and grown in media containing glucose as the carbon source. The bioflocculation efficiency was depended on the pH, carbon sources, the initial algae concentrations, bacteria strains, and the inital bioflocculant-producing bacteria concentrations. The temperature lightly affected the bioflocculation, no noticeable behavioral or activity changes were observed in mice that were orally administrated with four bacterial strains, and no treatment-related illness or death occurred after 72 hours. In general, the bioflocculation process is easy to operate, cost-effective, environment-friendly and therefore, it can be applied for industrial processing of microalgae.


Biofloccuation, bacteria, algae concentrations, Lamdong, Vietnam


Published by Vietnam Academy of Science and Technology