Extracellular polymeric substances synthesis by Cloacibacterium was affected by different concentrations of glycerol in the medium. The concentration of EPS in 72 h fermentation was increased from 13 g/L with no external carbon supplementation to 21.3 +/- 0.7 g/L with 2% (w/v) crude glycerol addition. Physical and chemical extraction methods (heating, centrifugation and ethylene diamine tetra-acetic acid (EDTA)) were used in this study and their performance to extract EPS was compared. A significant variation in concentration of extracted B-EPS (broth-EPS) by heating (20.8 +/- 0.5 g/L) and centrifugation (21.3 +/- 0.7 g/L) extraction methods was not observed. However, in case of extraction with EDTA (5 g/L), the B-EPS concentration extracted was 25.5 +/- 0.9 g/L, which exhibited high flocculation activity of 95.3 +/- 0.5% at optimum dose of 23.1 mg B-EPS/g kaolin. Moreover, Ni removal efficiency of 80% from primary treated wastewater was achieved using 35 mg/L of B-EPS extracted by centrifugation method. (C) 2016 Elsevier Ltd. All rights reserved.