Microcalorimetric investigation of the growth of the Escherichia coli DH5α in different antibiotics

The effects of Amoxicillin Sodium and Cefuroxime Sodium on the growth of E. coli DH5 alpha were investigated by microcalorimetry. The metabolic power-time curves of E. coli DH5 alpha growth were determined by using a TAM air isothermal microcalorimeter at 37 degree C. By evaluation of the obtained parameters, such as growth rate constants (k), inhibitory ratio (I), the maximum heat power (P sub(m)) and the time of the maximum heat power (t sub(m)), one found that the inhibitory activity of Amoxicillin Sodium vs. E. coli DH5 alpha is enhanced with the increasing of the Amoxicillin Sodium concentration, and the Cefuroxime Sodium has a stimulatory effect on the E. coli DH5 alpha growth when the concentration is about 1 mu g mL super(-1). The IC sub(50) for the Amoxicillin Sodium and the Cefuroxime Sodium are 1.6 and 2.0 mu g mL super(-1), respectively, it implicates that the E. coli DH5 alpha is more sensitive to Amoxicillin Sodium than Cefuroxime Sodium.