MICROBIAL DETECTION BY A GLUCOSE BIOSENSOR COUPLED TO A MICRODIALYSISFIBER

The use of a glucose biosensor coupled to microdialysis sampling in a flow injection analysis system is described to follow the growth of Es cherichia coli in a glucose-containing liquid culture medium. The expe rimental set-up permitted a throughput rate of 25 samples h(-1). curve s were modelled by a modified Gompertz equation, which permitted the d etermination of lag time and maximum specific growth rate. The time re quired to produce an appreciable variation in the biosensor response ( minimum detection time, MDT) was determined. A plot of MDT versus micr obial concentration was found to be linear in the range 10(6)-10(10) c olony forming units (cfu) ml(-1). A microbial concentration of 10(6) c fu ml(-1) detected after about 5 h.