ABSTRACT
The industrial process using solvent-producing Clostridium species traditionally has been a batch process, characterized by the initial growth or acidogenic phase, followed by the stationary or solventogenic growth phase, which culminates ultimately in sporulation [1]. The regulation and factors involved in triggering the transitions from the early phase to the solventogenic phase, as well as the factors that affect sporulation, are complex and have been the subject of much research [1,2]. When molasses, which is deficient in nitrogen, replaced the historical corn mash, the industrial process became more complex because nitrogenous compounds had to be added to the sugar-based medium [3]. Solvent yield was affected by the nitrogen source; however, the effect is difficult to analyze in a complex medium. The use of soluble, chemically defined media for laboratory studies is complicated by pH control issues because the buffering capacity of the medium is significantly reduced when ammonia salts or amino acids replace less metabolizable proteins and peptides.
