A Procedure to Determine the Uncertainties in Kinetic Parameters Obtained by Extant Respirometry

摘要

Kinetic parameters obtained experimentally should be reported as mean values with confidenceintervals that incorporate the uncertainties encountered in fitting experimental data to a nonlinearmodel. A source of uncertainty unique to respirometry is the separation of the experimentaloxygen consumption rate data into endogenous and exogenous components. A portion of thedata is used to estimate the endogenous rate that is then subtracted from the measured oxygenconsumption rate to “normalize” the data before the kinetic parameters are estimated by fittingthe model to the exogenous oxygen consumption. This paper proposes a procedure toincorporate the uncertainties of respirometric data normalization with the other uncertainties todefine a two dimensional confidence region for Monod model parameters including an approachto express the confidence region in a simple numerical form. Using this approach wedemonstrate that normalization using post-exogenous (rather than pre-exogenous) dataminimizes uncertainty in the K_s estimate.