Involvement of pyruvate dehydrogenase in product formation in pyruvate-limited anaerobic chemostat cultures of Enterococcus faecalis NCTC 775.
Enterococcus faecalis NCTC 775 was grown anaerobically in chemostat culture with pyruvate as the energy source. At low culture pH values, high in vivo and in vitro activities were found for both pyruvate dehydrogenase and lactate dehydrogenase. At high culture pH values the carbon flux was shifted towards pyruvate formate lyase. Some mechanisms possibly involved in this metabolic switch are discussed. In particular attention is paid to the NADH/NAD ratio (redox potential) and the fructose-1,6-bisphosphate-dependent lactate dehydrogenase activity as possible regulatory factors.
Snoep
J L
JL
Department of Microbiology, University of Amsterdam, The Netherlands.
Teixeira de Mattos
M J
MJ
Postma
P W
PW
Neijssel
O M
OM
D000123:Acetyltransferases / Q000378:metabolism; D000693:Anaerobiosis; D013293:Enterococcus faecalis / Q000201:enzymology*; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*; D011773:Pyruvates / Q000378:metabolism*; D019289:Pyruvic Acid
D011768:Pyruvate Dehydrogenase Complex; D011773:Pyruvates; D009243:NAD; D019289:Pyruvic Acid; D007770:L-Lactate Dehydrogenase; D000123:Acetyltransferases; C022560:formate C-acetyltransferase