ONLINE MONITORING OF THE METHANOGENIC FERMENTATION BY MEASUREMENT OF CULTURE FLUORESCENCE

Real-time on-line fluorescence measurements of the coenzymes NAD(P)H and F420 were evaluated as indicators of stability in a glucose-fed anaerobic methanogenic digester. A probe designed for in situ fluorimetric measurement of NAD(P)H provided an assessment of activity of the total microbial community, while the response of a fluorescence probe designed to measure coenzyme F420 correlated well with methanogenic activity. The two fluorescence-monitoring probes responded directly to fermentation imbalance during periods of substrate overloading and corresponded to traditional offline measurements, suggesting that the probes may be suitable candidates for inclusion in an on-line process control system for anaerobic digestion. © 1990 Kluwer Academic Publishers.