KINETICS OF ACTION OF SCHIFF-BASES ON AEROBACTER-AEROGENES AS STUDIEDBY MICROCALORIMETRY

Microcalorimetry was used to study the kinetics of action of five kind s of Schiff base on a strain of Aerobacter aerogenes. Differences in t heir capacities to suppress the metabolism of this bacterium were obse rved. The extent and duration of the inhibitory effect on the metaboli sm as judged from the multiplication rate constant, k, varied with the different Schiff bases. The multiplication rate constants, k, of Aero bacter aerogenes (in log phase) in the presence of Co(III)-NG and Ni-N G (NG: D-glucosamine-beta-naphthol aldehyde) decreased with the increa sing concentrations of the compounds C, but the relationship between k and C was not of good linearity. For Fe(III)-NG, the multiplication r ate constants are constant irrespective of variations in concentration . Similarly over the concentration range 50-200 mu g mL(-1,) there is nearly change in the inhibitory effects of NG on Aerobacter aerogenes, while they are slightly reduced beyond 200 mu g mL(-1). The experimen tal results revealed that the sequence of antibiotic activity of Schif f base drugs is: Co(III)-NG > Ni-NG > NG > Fe(III)-NG.