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Adaptation of the “Dynamic Method” for measuring the specific respiration rate in oxygen transfer systems through diffusion membrane
Author(s) -
Pamboukian Marilena Martins,
Pereira Carlos Augusto,
Augusto Elisabeth de Fatima Pires,
Tonso Aldo
Publication year - 2011
Publication title -
biotechnology journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.144
H-Index - 84
eISSN - 1860-7314
pISSN - 1860-6768
DOI - 10.1002/biot.201000273
Subject(s) - bioreactor , respiration , aeration , biological system , diffusion , membrane , oxygen , chemistry , clark electrode , mass transfer , biochemical engineering , chromatography , biology , thermodynamics , biochemistry , botany , physics , organic chemistry , engineering , electrode , electrolyte
Monitoring the specific respiration rate(Q O2 ) is a valuable tool to evaluate cell growth andphysiology. However, for low Q O2 values the accuracy may depend onthe measurement methodology, as it is the case in animal cell culture. The widely used “Dynamic Method” imposes serious difficulties concerning oxygen transfer cancellation, especially through membrane oxygenation. This paper presents an improved procedure to this method, through an automated control of the gas inlet composition that can minimize the residual oxygen transfer driving force during the Q O2 measurement phase. The improved technique was applied to animal cell cultivation, particularly three recombinant S2 ( Drosophila melanogaster ) insect cell lines grown in a membrane aeration bioreactor. The average measurements of the proposed method reached 98% of stationary liquid phase balance method, taken as a reference, compared to 21% when the traditional method was used. Furthermore, this methodology does not require knowledge of the volumetric transfer coefficient k L a, which may vary during growth.