Comparison of CFU obtained through MBRT and that obtained through direct measurement from agar plate method. (a) Symbol open circle represents data obtained from agar plate method. Continuous line represents equivalent CFU determined by MBRT. Maximum error in the estimation was 18%. (b) Effect of different initial concentration of total cell count on the growth of mixed culture. Solid line (CFU equivalent from MBRT) and the symbol open triangle (data from agar plate method) are for an initial cell concentration of 104 cells/ml. Dashed line (CFU equivalent from MBRT) and the symbol open circle (data from agar plate method) is for an initial cell concentration of 102 cells/ml. It can be seen that the MBRT is able to predict the effect of initial cell concentration. (c) Fraction of individual species to total metabolic active cell count for the mixed culture of E. coli and B. subtilis. Symbol open triangle and open circle represent E. coli and B. subtilis respectively.