A NEW PIEZOELECTRIC RESPONSE MODEL FOR POPULATION-GROWTH OF BACTERIA

A piezoelectric response model on the population growth of microorgani sm is proposed. This model is based on a novel population growth model , which has a more obvious ecological meaning and the fact that the se ries piezoelectric quartz crystal (SPQC) sensor responses to conductiv ity changes of the medium during the growth of the microorganism. From the response model four parameters can be obtained including the maxi mum specific growth rate mu(m), saturated population size N-m, and two constants C and K-1. The influence of the parameters on the response curve is discussed in which the influences of mu(m), and N-m are more obvious. With the proposed model the quantitative determination of bac teria may be more accurate than the frequency detection time (FDT) met hod. Then the growth of Escherichia coliform (E. coli) monitored with a SPQC sensor is compared with the simulated growth curve obtained by the proposed model and a good agreement is obtained. (C) 1998 Elsevier Science B.V. All rights reserved.