Carbon and energy balances in cell-recycle cultures of Schizosaccharomyces pombe.
A strain of the fission yeast Schizosaccharomyces pombe was aerobically grown in a cell-recycle fermentor under various operating conditions, i.e., different bleeding rates and various separate feed rates of glucose and basal medium. Carbon and energy balances were analyzed during steady-state culture regimes, allowing growth yields and maintenance coefficients to be determined under glucose-limited and glucose-excess environments. Special attention was given to the metabolic shift from purely oxidative to respirofermentative glucose catabolism resulting from a change in the growth-limiting factor. No maintenance requirements for the carbon source and for energy were observed during glucose-limited culture regimes and oxidative catabolism. Under glucose excess and respirofermentative metabolism, the m(G) coefficient was shown to be growth-linked, whereas the enhancement of the apparent m(e) coefficient observed for increased residual glucose concentrations could be assigned to a decline in the ATP yield.
Uribelarrea
J L
JL
Centre de Transfert en Biotechnologie-Microbiologie, Département de Génie Biochimique et Alimentaire, URA-CNRS-544, Institut National des Sciences Appliquées, Complexe Scientifique de Rangueil, F-31077 Toulouse Cédex, France.
De Queiroz
H
H
Goma
G
G
Pareilleux
A
A