Microcalorimetric investigation of two cephalosporins on colon bacteria activity

The effects of cephradinum and ceftazidime on the metabolism of Escherichia coli (E. coli)  DH5α was determined by microcalorimetry.  The microbial activity was recorded as power-time curves through an ampoule method with a TAM Air Isothermal Microcalorimeter at 37 ℃.  The parameters such as the growth rate constant (k), inhibitory ratio (I), the maximum power output (P_m) and the time (t_m) corresponding to the maximum power output were calculated.  The results show that the ceftazidime has a better inhibitory effect on E.coli DH5α than cephradinum.