A new piezoelectric response model for population growth of bacteria

A piezoelectric response model on the population growth of microorganism is proposed. This model is based on a novel population growth model, which has a more obvious ecological meaning and the fact that the series piezoelectric quartz crystal (SPQC) sensor responses to conductivity changes of the medium during the growth of the microorganism. From the response model four parameters can be obtained including the maximum specific growth rate μ 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 μ m and N m are more obvious. With the proposed model the quantitative determination of bacteria may be more accurate than the frequency detection time (FDT) method. 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.