Determination of Kinetic and Stoichiometric Parameters of Pseudomonas putida F1 by Chemostat and In Situ Pulse Respirometry

Abstract

The applicability of pulse respirometry, for the estimation of kinetic and stoichiometric parameters in pure cultures was evaluated by comparison with traditional chemostat method. Pseudomonas putida F1 was cultured in a continuous stirred tank reactor, using glucose as sole carbon source. The reactor was operated under steady-state with six dilution rates, ranging from 0.06 to 0.35 h-1. Substrate and biomass concentration were measured and used to estimate kinetic and stoichiometric parameters, according to the Monod model. An in situ respirometry method was also applied to the reactor, with the injection of pulses of glucose from 19 to 97 mg L-1. The respirograms obtained were used to estimate the kinetic and stoichiometric parameters according to ASM1 and ASM3 models. No significance difference was observed between parameters estimated by chemostat and respirometric methods. The glucose affinity constant was from 0.4 to 0.7 mg L-1, the maximum specific growth rate was from varying from 0.14 to 0.20 h-1, and the growth yield was from 0.41 to 0.67. These results confirm that in situ pulse respirometry is a suitable method for kinetic and stoichiometric parameters estimation.