Conditions promoting stability of solventogenesis or culture degeneration in continuous fermentations of Clostridium acetobutylicum

摘要: The stability of solvent production by Clostridium acetobutylicum has been studied in continuous single-stage and two-stage fermentations. At low dilution rates, metabolic oscillations resulting from product inhibition have observed especially the case fermentations controlled accumulation. A second type instability also product-controlled fermentations, but not nitrogen limitation, was a long-term drift towards acid production. This shown to be identical phenomenon culture degeneration occurring upon subculturing batch fermentation. In addition, it found that could reversed decreases pH, temperature rate, growth limitation nitrogen-deficient conditions addition butyric acetic acids. existence two distinct mechanisms, short-term control (shift) (drift), both triggered same physiological conditions, is proposed regulation