Study of optimization of wastewater contaminant removal along with extracellular polymeric substances (EPS) production by a thermotolerant Bacillus sp ISTVK1 isolated from heat shocked sewage sludge

The present work involved study of wastewater contaminant removal along with EPS production by a thermotolerant bacterium Bacillus sp. ISTVK1, isolated from heat shocked sewage sludge. EPS production in basal and mineral medium containing 50% filter sterilized wastewater and 0.5% sucrose was found to be 0.83 +/- 0.12 g L-1 and 0.31 +/- 0.10 g L-1 culture, respectively. GC-MS analysis of EPS revealed the presence of beta-D-glucose, alpha-D-galactose and beta-D-arabinose. FT-IR spectrum confirmed the presence carbohydrates. Box-Behnken design was used to optimize process parameters for enhanced EPS production along with % COD reduction of wastewater. The optimised conditions when used in a 1.5 L bioreactor showed EPS production of 1.67 +/- 0.06 g L-1 culture and 93.0 +/- 0.21 % COD removal. (C) 2016 Elsevier Ltd. All rights reserved.