Ethanol Production from Desizing Wastewater using Co-Culture of Bacillus subtilis and Saccharomyces cerevisiae

This research studied the production of ethanol from desizing wastewater of dye-bleaching industry by using co-culture of Bacillus subtilis D (B) and Saccharomyces cerevisiae TISTR 5160 (S). This work began with the study of the growth of single culture of B and S in wastewater by varying incubation temperature. The optimum temperature for the growth of B and S was 37 degrees C and 30 degrees C, respectively. For co-culture, the order of S inoculation, the inoculum ratio of B to S, shaking effect, incubation temperature after S addition, and the effect of nitrogen sources were studied. The optimum condition for ethanol production of co-culture was shaking at 150 rpm and 37 degrees C with the inoculation of B 1 day before S and the inoculum ratio of B to S was 5:10. This gave the ethanol content of 5.8 g/L after 48 h. Addition of nitrogen sources prolonged the period the ethanol production going to the maximum. (C) 2015 The Authors. Published by Elsevier Ltd.