TY - JOUR
T1 - A stoichiometric analysis of biological xylitol production
AU - Aranda-Barradas, Juan S.
AU - Garibay-Orijel, Claudio
AU - Badillo-Corona, Jesús A.
AU - Salgado-Manjarrez, Edgar
N1 - Funding Information:
The authors gratefully acknowledge the Research Office of the National Polytechnic Institute (SIP-IPN) and the National Council for Science and Technology (CONACyT) of Mexico for the financial support. Some of the experimental techniques were developed in the Bioreactors and Fermentations group at the Institut National Polytechnique de Toulouse (INP-T), France. Juan S. Aranda-Barradas thanks Marie-Line Delia-Dupuy Ph.D., for the technical assistance and the research facilities provided.
PY - 2010/6/15
Y1 - 2010/6/15
N2 - In the biological production of xylitol from xylose it has been demonstrated that a low-level supply of oxygen to the culture (∼0.1 volume of air per volume of culture medium per minute) yields an increase of extracellular accumulated xylitol up to 0.65g xylitolg xylose -1 in our experiments. In spite of the abundant experimental evidence regarding xylitol production, the advances in the mathematical description of the process are relatively scarce. In this work, a stoichiometric model considering the main biochemical reactions (metabolic fluxes) involved in microaerobic xylitol production is proposed. The main metabolic reactions in xylitol production by Candida parapsilosis were incorporated in order to establish a stoichiometric reaction rate analysis of the network. The reaction rates in the metabolic network were calculated both for determined and underdetermined systems. A comparison between predicted and experimentally measured or reported yields has shown that the proposed stoichiometric model correctly depicts the xylitol yield within a 12.8% average error for several xylose-assimilating yeasts. The expected xylitol concentrations for a production process were also estimated after a sensitivity analysis of the metabolic network. An analysis of the estimated metabolic fluxes provided insight into some physiological events involved in the production of xylitol by yeasts.
AB - In the biological production of xylitol from xylose it has been demonstrated that a low-level supply of oxygen to the culture (∼0.1 volume of air per volume of culture medium per minute) yields an increase of extracellular accumulated xylitol up to 0.65g xylitolg xylose -1 in our experiments. In spite of the abundant experimental evidence regarding xylitol production, the advances in the mathematical description of the process are relatively scarce. In this work, a stoichiometric model considering the main biochemical reactions (metabolic fluxes) involved in microaerobic xylitol production is proposed. The main metabolic reactions in xylitol production by Candida parapsilosis were incorporated in order to establish a stoichiometric reaction rate analysis of the network. The reaction rates in the metabolic network were calculated both for determined and underdetermined systems. A comparison between predicted and experimentally measured or reported yields has shown that the proposed stoichiometric model correctly depicts the xylitol yield within a 12.8% average error for several xylose-assimilating yeasts. The expected xylitol concentrations for a production process were also estimated after a sensitivity analysis of the metabolic network. An analysis of the estimated metabolic fluxes provided insight into some physiological events involved in the production of xylitol by yeasts.
KW - Candida parapsilosis
KW - Metabolic network
KW - Stoichiometric matrix
KW - Stoichiometric model
KW - Xylitol
KW - Xylose
UR - http://www.scopus.com/inward/record.url?scp=84856285075&partnerID=8YFLogxK
U2 - 10.1016/j.bej.2009.10.023
DO - 10.1016/j.bej.2009.10.023
M3 - Artículo
SN - 1369-703X
VL - 50
SP - 1
EP - 9
JO - Biochemical Engineering Journal
JF - Biochemical Engineering Journal
IS - 1-2
ER -