ORIGINAL PAPER Bioethanol production from rice bran with optimization of parameters by Bacillus cereus strain McR-3 ‘Fermentation of rice bran for fuel ethanol production’ S. Tiwari • S. K. Jadhav • K. L. Tiwari Received: 29 March 2014 / Revised: 28 November 2014 / Accepted: 30 December 2014 / Published online: 5 March 2015 Ó Islamic Azad University (IAU) 2015 Abstract The potential environmental benefits that can be obtained from replacing petroleum fuels with biofuels derived from renewable biomass sources are the main driving forces for promoting the production and use of biofuels. Due to depletion of fossil fuels, ethanol, which can be obtained via the bioconversion of renewable feed- stock, is widely regarded as an efficient alternative for gasoline as transportation fuel. Biomass energy can play an important role in reducing greenhouse gas emissions. Rice bran is a by-product of milling process of rice, and due to its carbohydrate contents, it may serve as good source for bioethanol production. The present study deals with bioe- thanol production from rice bran and screening of bioe- thanol-producing bacteria from rice bran. In the screening process, three fermentative bacteria were obtained; they were studied on the basis of morphology, biochemical characteristics and maximum bioethanol production. The maximum bioethanol-producing bacteria was identified by sequencing method. The bacteria thus identified as Bacillus cereus strain McR-3 is a novel bacteria reported in bioe- thanol production from rice bran substrate. Different pa- rameters like temperature and pH also affects the production of bioethanol. It was observed that optimum temperature and pH for maximum bioethanol production was 37 °C and 5, respectively. Keywords Biofuels  Energy  Fermentative bacteria  Parameters Introduction Worldwide interest is increasing in alternative sources of energy due to inevitable depletion of energy supply (Aristidou and Penttila 2000). The increase in the prices of petroleum-based fuels, strict government regulations on exhaust emissions and future depletion of worldwide pet- roleum reserves encourages studies searching for alterna- tive fuels (Harkin 2000; Howard 1994). The increasing concerns about environmental protection have led to the use of bioethanol as sole fuel, or a blend with gasoline (Tofighi et al. 2010). Biomass energy can play an important role in reducing greenhouse gas emissions because air pollution, especially in mega cities, figures prominently among the main environmental causes which affect human health (Pour et al. 2007). Environmental concerns and the desire to be less dependent on imported fossil fuel have intensified worldwide efforts for production of ethanol from starch- and sugar-producing crops (Kataria and Ghosh 2011). The production of ethanol has two routes: synthetic and biological. The synthetic ethanol production is com- monly carried out by a catalytic hydration of ethylene. Biological production of ethanol is from biomass with the involvement of living microorganisms. Alcoholic fermen- tation has been carried out using a number of sugary ma- terials depending upon their availability and suitability in particular geographic situations. The increasing need for bioethanol as an energy source has stimulated worldwide investigations in search of cheaper substrate for bulk ethanol production. The primary challenge with biofuels use is the availability of suitable feedstock in sufficient quantity for large-scale adoption. As an oxygenated com- pound, ethanol provides additional oxygen in combustion and hence obtains better combustion efficiency. The main environmental advantages of fuel ethanol are its S. Tiwari  S. K. Jadhav (&)  K. L. Tiwari School of Studies in Biotechnology, Pt. Ravishankar Shukla University, Raipur 492010, Chhattisgarh State, India e-mail: jadhav9862@gmail.com 123 Int. J. Environ. Sci. Technol. (2015) 12:3819–3826 DOI 10.1007/s13762-014-0746-1