Abstract
An apparatus for the measurement of bacterial growth is described. The instrument applies alternate adequate sequential currents of two different frequencies through a pair of electrodes immersed in a cultured medium. It monitors, detects and quantifies the growth of micro-organisms based on the measurement of the impedance across the two electrodes and, simultaneously, it measures the variation in the medium turbidity. The medium conductivity and the interface electrode impedance changes can be extracted from the measured impedance. The variations in turbidity can be calibrated in absorbance or optical density units. Moreover, all these parameters are also proportional to bacterial proliferation. The computer-controlled apparatus processes and displays the parameters on a monitor showing bulk resistance, electrode impedance and turbidity changes as time course events. The equipment can detect aerobic or anaerobic micro-organisms and permits the operator simultaneously to assess impedance and turbidity, or it can produce each parameter as a separate event. Time growth curves of different micro-organisms are presented in the results.
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References
Bishop, J. R., White, C. H., andFirstenberg-Eden, R. (1984): ‘Rapid impedimetric method for determining the potential shelf life of pasteurized whole milk’,J. Food Prod.,47, pp. 471–475
Bossuyt, R. G., andWaes, G. M. (1983): ‘Impedance measurements to detect post-pasteurization contamination of pasteurized milk’,J. Food Prod.,46, pp. 622–624
Crain, P. R. (1980): ‘Fundamental aspects of monitoring food related microbes by impedance’ PhD thesi, Washington University, Department of Food Science & Technology, USA
Deak, T., andBeuchat, L. R. (1993): ‘Comparison of conductimetric and traditional plating techniques for detecting yeasts in fruit juices’,J. Appl. Bacteriol.,75, pp. 546–550
Dezenclos, T., Ascon-Cabrera, M., Ascon, D., Lebeault, J.-M., andPauss, A. (1994): ‘Optimization of the indirect impedancimetry technique; a handy technique for microbial growth measurement’,Appl. Micobiol. Biotechnol.,42, pp. 232–238
Felice, C. J., Madrid, R. E., Olivera, J. M., Rotger, V. I., andValentinuzzi, M. E. (1999): ‘Quantification of bacterial content in milk by means of interface reactance growth curves’,J. Microbiol. Meth.,35, (1): pp. 37–42
Felice, C. J., Olivera, J. M. andLópez, R. (1991): ‘Sistema multicanal para la detección de microorganismos’,Mundo Electrónico, Barcelona, Spain, pp. 55–58
Felice, C. J. Seggiaro, V. N., andValentinuzzi, M. E. (1992): ‘Input amplifier current components in the electrode interface impedancimetric bacterial growth curves’. Proc 14th Ann. Int. Conf. IEEE/EMBS, Paris, France, pp. 2763–2764
Felice, C. J., Valentinuzzi, M. E., Vercellone, M. I., andMardid, R. E. (1992a): ‘Impedance bacteriometry: medium and interface contributions during bacterial growth’,IEEE Trans.,BME-39, pp. 1310–1313
Felice, C. J. (1995): ‘Monitor digital de microorganismos: Aspectos teóricos y tecnológicos’. PhD thesis, Universidad Nacional de Tucumán, Tucumán, Argentina (in Spanish)
Firstenberg-Eden, R., andEden, G. (1984): ‘Impedance microbiology’, (Wiley, New York)
Geddes, L. A., Da Costa, C. P., andWise, G. (1971): ‘The impedance of stainless-steel electrodes’,Med. Biol. Eng.,9, pp. 511–521
Hashimoto, H., Miike, H., Ebina, Y., andMiyaji, T. (1979): ‘A method of detecting bacteria in culture medium by simultaneous measurements of electrical impedance and turbidity’. Faculty of Engineering, Yamaguchi University, Tokiwadai, UBE, Japan
Hashimoto, H., Ebina, Y., Miike, H., andMiyaji, T. (1981): ‘An automated method for identifying bacteria by simultaneous measurement of electrical impedance and turbidity’,Proc. Vth ICEBI, Tokyo
Madrid, R. E., Vercellone, M. I., Felice, C. J., andValentinuzzi, M. E. (1994): ‘Multichannel bacterial growth analyzer by impedance and turbidity’,Med. Biol. Eng. Comput.,32, pp. 670–672
Madrid, R. E., Spinelli, E. M., andFelice, C. J. (1998): ‘Sinusoidal fitting using exact linearization applied to bioimpedancimetric measurements’. Proc. 20th Ann. Int. Conf. IEEE/EMBS, Hong Kong, China
Madrid, R. E. (1998): ‘Analizador digital electro-óptico: Aplicación simultánea de ambos métodos como herramienta de automatización en microbiología’ PhD thesis, Universidad Nacional de Tucumán, Tucumán, Argentina (in Spanish)
Morucci, J. P., Valentinuzzi, M. E., Rigaud, B., Felice, C. J., Chauveau, N., andMarsili, P. M. (1996): ‘Bioelectrical impedance techniques in medicine’,Crit. Rev. Biomed. Eng.,24 (4–6), pp. 221–677
Neviani, E., andVeneroni, A. (1991): ‘Utilizzazione di analisi conduttimetriche per la valutazione della contaminazione microbica di latti in polvere’,Scienza e Tecnica Lattiero-Casearia,42, pp. 111–125
O'Connor, F. (1982): ‘An impedance method for the determination of bacterial quality of raw milk’,Kieler Milchwirtschaftliche Forschungsberichte,34, pp. 123–128
Owens, J. D., Thomas, D. S., Thomson, P. S., andTimmerman, J. W. (1989): ‘Indirect conductimetry: a novel approach to the conductimetric enumeration of microbial populations’,Lett. App., Microbiol.,9, pp. 245–249
Pallás-Areny, R., andWebster, J. (1991): ‘Sensors and signal conditioning’ (John Wiley & Sons, USA)
Schwan, H. P. (1963): ‘Determination of biological impedances’in Nastuk, W. L. (Ed.), ‘Physical techniques in biological research. VI, Part B, Electrophysiological Methods’ (Academic Press, New York), chap. 6, pp. 323–407
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Madrid, R.E., Felice, C.J. & Valentinuzzi, M.E. Automatic on-line analyser of microbial growth using simultaneous measurements of impedance and turbidity. Med. Biol. Eng. Comput. 37, 789–793 (1999). https://doi.org/10.1007/BF02513383
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DOI: https://doi.org/10.1007/BF02513383