Springer Online Journal Archives 1860-2000
Process Engineering, Biotechnology, Nutrition Technology
Summary Viable cell numbers were determined with an electrode system composed of a membrane filter for retaining microorganisms and an oxygen electrode. The principle of the cell number determination is based on sensing microbial respiration. The response time of the system was 10 min. A linear relationship was obtained between the current and the cell numbers ofEscherichia coli, Bacillus subtilis, Flavobacterium arabrescence, Saccharomyces cerevisiae, andTrichosporon cutaneum on the membrane filter. The current was reproducible, with an average relative error of 5% when the electrode contained 2×108 Escherichia coli. A good agreement (a correlation coefficient; 0.98 in 10 experiments) was obtained, when the cell populations ofE. coli were determined by the proposed method and colony counts. The minimum measurable cell populations were 106 cells per ml with the bacteria and 105 cells per ml with the yeasts.
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