Preliminary Screening of Mutagens with a Microbial Sensor

Preliminary screening of mutagens Is achieved with a microbial sensor composed of two microbial electrodes using a recombinant deficient strain, Bacillus subtllls (Rec^-), and a wild strain, B. subtllls (Rec⁺). The principle of the sensor Is based on the Inhibitory action of the mutagens on the respiration of B. subtllls (Rec^-). When chemical mutagens were added to the system, the current of the Rec^- electrode gradually Increased and that of the Rec+ electrode did not Increase. Linear relationships were obtained between the rate of the current increase of the Rec- electrode and the mutagen concentration. Such responses were not obtained when the antibiotics, respiration Inhibitors, and bactericides were employed to the sensor.