The Substrate Carbon Consumption and Metabolite Production to Describe the Growth of Geotrichum candidum and Penicillium camemberti on Glucose and Amino Acids

Fadila Ayati1, Majda Aziza2, Rachida Maachi1 and Abdeltif Amrane3*

1Kinetics and Applied Catalysis Laboratory, Mechanical and Process Engineering College, USTHB, B.P. 32, Bab Ezzouar – El Alia, 16111, Algeria

2Center for Renewable Energy Development, B.P. 62, Route de l'Observatoire, Village céleste, Bouzaréah, Algiers, Algeria
3Chemistry and Process Engineering, University of Rennes 1/ENSCR UMR CNRS 6226 'Chemical Sciences of Rennes', ENSCR, avenue du Général Leclerc, FR-35708 Rennes Cedex 7, France

Article history:

Received October 20, 2008
Accepted December 23, 2009

Key words:

batch culture, carbon substrates, Geotrichum candidum, Penicillium camemberti, unstructured models, biomass yield


Amino acids had previously been characterized based on their ability to be assimilated as carbon sources by Penicillium camemberti and Geotrichum candidum. For each microorganism, three groups of amino acids have been characterized, leading to four different metabolic behaviours. To describe those recorded during P. camemberti growth on an amino acid and glucose, an unstructured model had previously been developed, based on the sequential consumption of both carbon substrates; glucose first, followed after its exhaustion by the selected amino acid. Only the part of the amino acid assimilated as a carbon source for cellular biosynthesis was considered in the model, which had to be deduced from the total amino acid consumption. To avoid the use of such an indirect parameter, ammonium was considered in this work, which was produced after amino acid deamination and corresponded to the release of the excess nitrogen, since amino acids contain excess nitrogen in relation to their carbon content in fungi. The model, therefore, involved substrate carbon consumption, ammonium production, as well as biomass yield on the carbon substrate, YX/S, and biomass yield on the produced ammonium, YX/P. The model proved to describe satisfactorily the various metabolic behaviours recorded during P. camemberti and G. candidum growth on an amino acid and glucose.


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