Abstract: In one aspect, methods to enhance the production of ethanol and other fermentive end products from a wide variety of feedstocks by Clostridium microorganisms, such as Clostridium phytofermentans are disclosed. A method of improving fermentation performance of Clostridium microorganisms, such as Clostridium phytofermentans through the use of a fed-batch strategy is described, as well as methods of producing fermentive end products, such as alcohols and/or chemicals by fermenting Clostridium microorganisms, such as Clostridium phytofermentans in the presence of fatty acid-containing compounds and/or at reduced pH.