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 β-d-glucose, α-d-galactose and β-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.