Kinetic and stoichiometric characterization of organoautotrophic growth of Ralstonia eutropha on formic acid in fed-batch and continuous cultures.
Microb Biotechnol
; 8(1): 155-63, 2015 Jan.
Article
en En
| MEDLINE
| ID: mdl-25123319
ABSTRACT
Formic acid, acting as both carbon and energy source, is a safe alternative to a carbon dioxide, hydrogen and dioxygen mix for studying the conversion of carbon through the Calvin-Benson-Bassham (CBB) cycle into value-added chemical compounds by non-photosynthetic microorganisms. In this work, organoautotrophic growth of Ralstonia eutropha on formic acid was studied using an approach combining stoichiometric modeling and controlled cultures in bioreactors. A strain deleted of its polyhydroxyalkanoate production pathway was used in order to carry out a physiological characterization. The maximal growth yield was determined at 0.16 Cmole Cmole(-1) in a formate-limited continuous culture. The measured yield corresponded to 76% to 85% of the theoretical yield (later confirmed in pH-controlled fed-batch cultures). The stoichiometric study highlighted the imbalance between carbon and energy provided by formic acid and explained the low growth yields measured. Fed-batch cultures were also used to determine the maximum specific growth rate (µmax = 0.18 h(-1) ) and to study the impact of increasing formic acid concentrations on growth yields. High formic acid sensitivity was found in R eutropha since a linear decrease in the biomass yield with increasing residual formic acid concentrations was observed between 0 and 1.5 g l(-1) .
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Bases de datos:
MEDLINE
Asunto principal:
Reactores Biológicos
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Cupriavidus necator
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Formiatos
Idioma:
En
Revista:
Microb Biotechnol
Año:
2015
Tipo del documento:
Article
País de afiliación:
Alemania