Recycling of carbon dioxide by free air CO2 enriched (FACE) Bacillus sp SS105 for enhanced production and optimization of biosurfactant

Carbon dioxide utilizing bacterium Bacillus sp. SS105 was isolated from FACE (free air CO2 enriched) sample. The strain was grown in shake flask containing minimal salt medium with 50 mM NaHCO3 as autotrophic carbon source and molasses as a low cost byproduct for mixotrophic growth. Carbon dioxide sequestration property of Bacillus sp. SS105 was determined by enzyme assay of carbonic anhydrase and ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO). Along with CO2 sequestration this strain produced biosurfactant and its characterization by FTIR and H-1 NMR indicated lipopeptide nature. Optimization of process parameter along with nutrient sources for higher biosurfactant production was done by Response Surface Methodology (RSM). Under optimized conditions, the yield of biosurfactant and biomass was 2.65 and 2.78 g L-1 respectively. The study revealed simultaneous CO2 sequestration and biosurfactant production by Bacillus sp. SS105. (C) 2017 Elsevier Ltd. All rights reserved.