Fig nbsp xA Voltage across the capacitor in

5. Conclusions
AcknowledgmentThis material is based upon work supported by the National Science Foundation under grant numbers CMMI-0745753, CMMI-0926791, and EEC-1132482 and the Mitsui USA Foundation.
Isolation; Characterization; Biobutanol; Clostridium; Renewable energy
1. Introduction
Although there have been numerous efforts to improve biobutanol production by genetically manipulating solvent-producing Clostridium species [9], genetically manipulated clostridia can be unstable [10]. Thus, screening for novel solvent-producing Clostridium strains that have the ability to produce large quantities of biobutanol and are able to ferment a wide range of sugars and agriculture wastes is of great importance to the field of biofuels.
The substrate cost in butanol Ginsenoside Rg1 contributes to 63% of the total production cost [7]. The use of low cost and renewable feedstock can reduce butanol production costs. Utilization of agricultural biomass in butanol production have already been achieved including palm oil mill effluent, rice bran, deoiled rice bran, corn stover, corn fiber, wheat barley, wheat bran, palm kernel cake, sago starch waste, rice straw, and wood chips [11], [12], [13] and [14]. Glycerol is a byproduct of the process of the transesterification of oils to biodiesel, and glycerol has been found to be a promising substrate for butanol fermentation because of its low-cost [15]. Approximately 10% of byproducts of biodiesel production is crude glycerol, which can be used for butanol production by Clostridia [16]. In this study, available agro-wastes and glycerol were fermented to biobutanol by the newly isolated strain of YM1 as inexpensive and renewable substrates.