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Modelling Xanthomonas campestris batch fermentations in a bubble column
Author(s) -
Pons A.,
Dussap C. G.,
Gros J. B.
Publication year - 1989
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260330404
Subject(s) - xanthomonas campestris , chemistry , oxygen , fermentation , yield (engineering) , respiration , bubble column reactor , bioreactor , biochemistry , chromatography , biomass (ecology) , bubble , botany , organic chemistry , thermodynamics , biology , ecology , physics , parallel computing , gas bubble , computer science , gene
Rate and yield expressions relating to biomass and xanthan formation and to nitrogen, glucose, and oxygen consumption were established for Xanthomonas campestris batch fermentations in a bubble column. Microbial growth was described by the logistic rate equation, characterized by a maximum specific growth rate μ M = 0.5 h −1 and a maximum attainable cell concentration provided by nitrogenous compounds. With regard to carbon metabolism, the decrease with time in experimental yields and in the experimental specific rates of xanthan production and glucose assimilation demonstrated the inadequacy of the Luedeking–Piret model. These decreases were connected to the simultaneous drop in dissolved‐oxygen tension observed during xanthan synthesis. The knowledge of metabolic pathways and energetic balance were used to establish the relationships between substrate utilization, ATP generation, and xanthan production. The model was structured by assuming the oxygen limitation of both the respiration rate and the efficiency of the oxidative phosphorylation mechanism (P/O ratio). Consequently, the specific rates and yield expressions became dependent on the dissolved‐oxygen tension, i.e., of the volumetric oxygen transfer in the fermentor.