Bioethanol is a promising biofuel and has a lot of great prospective and could become an alternative to fossil fuels. Ethanol fermentation using glycerol as carbon source was carried out by local isolate, ethanologenic bacterium Escheric h ia coli SS1 in a close system. Factors affecting bioethanol production from pure glycerol were optimized via response surface methodology (RSM) with central composite design (CCD). Four significant variables were found to influence bioethanol yield; initial pH of fermentation medium, substrate concentration, salt content and organic nitrogen concentration with statistically significant effect (p≤0.05) on bioethanol production. The significant factor was then analyzed using central composite design (CCD). The optimum conditions for bioethanol production were substrate concentration at 34.5g/L, pH 7.61, and organic nitrogen concentration at 6.42g/L in which giving ethanol yield approximately 1.00mol/mol. In addition, batch ethanol fermentation in a 2L bioreactor was performed at the glycerol concentration of 20g/L, 35g/L and 45g/L, respectively. The ethanol yields obtained from all tested glycerol concentrations were approaching theoretical yield when the batch fermentation was performed at optimized conditions. © 2014.
Adnan, N. A. A., Suhaimi, S. N., Abd-Aziz, S., Hassan, M. A., & Phang, L. Y. (2014). Optimization of bioethanol production from glycerol by Escheric h ia coli SS1. Renewable Energy, 66, 625–633. https://doi.org/10.1016/j.renene.2013.12.032