Analysis of glucose carbon fluxes in continuous cultures of Bacillus thuringiensis |
| |
Authors: | C F Mignone C Avignone-Rossa |
| |
Institution: | (1) Centro de Investigación y Desarrollo en Fermentaciones Industriales, CINDEFI, Facultad de Ciencias Exactas, UNLP, Calle 47 y 115, (1900) La Plata, Argentina. Fax: +54–21–25 4533 E-mail:〈mignone@nahuel.biol.unlp.edu.ar〉, AR |
| |
Abstract: | The glucose carbon fluxes in continuous cultures of Bacillus thuringiensis grown in a complex medium have been studied as a function of the growth rate. The results are discussed in the light of a
growth model. From reduced nicotinamide adenine dinucleotide (NADH) and carbon balances it was determined that the fraction
of glucose consumed for biomass synthesis decreased with the growth rate, while the glucose flux through the tricarboxylic
acid (TCA) cycle diminished after a threshold value of D=0.34 h-1, where D=dilution rate. At the highest growth rate tested, glucose was used almost exclusively as the energy source, via fermentative
pathways, which indicates that the yeast extract was used as the carbon source. The specific rate of oxygen consumption increased
with growth even after the beginning of the accumulation of acids, indicating that the respiratory chain was not saturated.
The results suggest that there is a mismatch between glycolysis and TCA cycle capacity, depending on the growth rate. Furthermore,
values of (P/O) ratio and m
ATP are presented, where (P/O) is mole of ATP formed per gram atom oxygen consumed by the respiratory chains and m
ATP is the maintenance requirement for ATP.
Received: 6 September 1995/Received last revision: 13 February 1996/Accepted: 20 February 1996 |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|