Abstract
A biosensor system is described for the rapid determination of cell number of Enterococcus seriolicida in a biological sample. The system consisted of E. seriolicida immobilized on a membrane, Clark-type oxygen electrode, and STAN-P culture medium.The STAN-P medium consisted of sodium
azide, a bacterial inhibitor which suppressed the growth of most microorganisms, but not E. seriolicida. The number of E. seriolicida organisms was determined by measuring the oxygen consumption of the cells with an oxygen electrode. The optimum conditions for carrying out the preparation of microorganisms were as follows: incubation temperature, 37°; incubation time, 1 hr, and concentration of sodium aside, 0.3g/l. A linear relationship was obtained between the output current of the sensor and
the number of E. seriolicida cells, which ranged from 1.4×107-7.2×107 cells/ml. The time required for
a single assay, including the preparation of microorganisms, was 2 hr.
