Performance of calorimetric methods for the investigation of microbial systems in combination with additional sensors.
Calorimetric methods are used in combination with online oxygen measurement (using an amperometric sensor) and determination of the optical density (using a fibre optic sensor) to investigate microbial growth behaviour. The calorimetric curves of different batch experiments show a characteristic and reproducible course. Changes in the slope of the DeltaT-time curves indicate the effects of limiting factors on the microbial activity during the cultivation. A first limitation could be correlated with the depletion of oxygen in the medium; a second correlates with the depletion of the carbon source. Measurements of optical density in some cases provide reliable information about the growth of a microorganism culture. Our measurements show a good correlation of the universal calorimetric signal (heat-time curve) to the signal of the miniaturised photometric (OD) sensor.
Ullrich
F
F
Fakultät für Chemie und Physik, Technische Universität Bergakademie Freiberg, Leipziger Strasse 29, Clemens-Winkler-Bau, 09599 Freiberg, Germany.
Winkelmann
M
M
Hüttl
R
R
Wolf
G
G
D002151:Calorimetry / Q000295:instrumentation* / Q000379:methods; D049109:Cell Proliferation; D002470:Cell Survival; D015169:Colony Count, Microbial / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation / Q000379:methods; D010100:Oxygen / Q000032:analysis* / Q000378:metabolism; D010231:Paracoccus denitrificans / Q000302:isolation & purification* / Q000378:metabolism*; D010783:Photometry / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018511:Systems Integration; D014159:Transducers
D010100:Oxygen