Ethanol from lignocellulosic materials fermentation

Ethanol from Lignocellulosic Materials Pretreatment, Acid and Enzymatic Hydrolyses, and Fermentation... 

Ballesteros, M., OUva, J. M., Negro, M. J., Manzanares, P., Ballesteros, I. (2004). Ethanol from lignocellulosic materials by a simultaneous saccharification and fermentation process (SFS) with Kluyveromyces marxianus CECT 10875. Process Biochemistry, 39, 1843—1848. 

Second-generation biofuel technologies make use of a much wider range of biomass feedstock (e.g., forest residues, biomass waste, wood, woodchips, grasses and short rotation crops, etc.) for the production of ethanol biofuels based on the fermentation of lignocellulosic material, while other routes include thermo-chemical processes such as biomass gasification followed by a transformation from gas to liquid (e.g., synthesis) to obtain synthetic fuels similar to diesel. The conversion processes for these routes have been available for decades, but none of them have yet reached a high scale commercial level. 

Feedstock Options. Ethanol may be produced via fermentation (with yeast) of 6-carbon or 12-carbon sugars from a number of carbohydrate sources including sugar crops, starch crops, or lignocellulosic materials. 

In direct microbial conversion of lignocellulosic biomass into ethanol that could simplify the ethanol production process from these materials and reduce ethanol production costs, Clostridium thermocellum, a thermoanaerobe was used for enzyme production, hydrolysis and glucose fermentation (755). Cofermentation with C thermosaccharolyticum simultaneously converted the hemicellulosic sugars to ethanol. However, the formations of by-products such as acetic acid and low ethanol tolerance are some drawbacks of the process. Neurospora crassa produces extracellular cellulase and xylanase and has the ability to ferment cellulose to ethanol 139). 

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