METABOLIC MONITORING BY USING THE RATE OF CHANGE OF NAD(P)H FLUORESCENCE

The amino acid fermentation by Corynebacterium glutamicum was monitore d with a new technique that uses the first derivative of the NAD(P)H f luorescence signal. The rate of change of NAD(P)H pools is indicative of intracellular redox balance variations that correspond to metabolic changes. The profile of this signal showed several characteristics th at coincided with major metabolic events during fermentation. We show here that the derivative fluorescence signal can accurately estimate p oints of threonine depletion, viable cell count, and the end of amino acid formation. Furthermore, on-line optimization strategies can be de veloped by using the derivative fluorescence signal. (C) 1994 John Wil ey and Sons, Inc.