Studies

Determination of essential amino acids for Streptococcus pyogenes M49

Lactic acid bacteria generally use homolactic fermentation for generation of ATP. Here we studied the role of Arginine and Glutamine metabolism on the general physiology of the lactic acid bacteria Streptococcus pyogenes. A deletion mutant of glnA (glutamine synthetase) has been constructed in the S. pyogenes M49 591 background. The glnA mutant strain shows decreased growth in low glutamine and excess glutamate conditions and no growth at all in low glutamine and low glutamate conditions. An arcA ...

The reconstruction of the metabolic networks is done by sequence comparison with already annotated genomes of L. lactis, L. plantarum, B. subtilis and E. coli

Here you will find all pre-liminary data

Pyruvate kinase (PYK, EC 2.7.1.40) is a key step in glycolysis converting phosphoenolpyruvate into pyruvate. The activity of PYK is activator-dependent, with the allosteric activation mostly being due to fructose-1,6-bisphosphate (FBP).

Pyruvate formate-lyase (PFL) is an important enzyme in the metabolic pathway of lactic acid bacteria (LAB) and is held responsible for the regulation of the shift between homolactic acid to mixed acid fermentation. PFL catalysis the reversible reaction of acetyl-CoA and formate into pyruvate and CoA. A glycyl radical, who is regenerated within the reaction, is involved; therefore, PFL works only under strictly anaerobic conditions. For its activation, the C-terminal domain has to bind to the ...

The two lactic acid bacteria L. lactis and S. pyogenes were studied with respect to the concentration of intracellular metabolites involved in glycolysis in time upon a glucose pulse. Models that describe this behavior are also constructed

Lactic acid bacteria generally use homolactic fermentation for generation of ATP. Here we studied the role of the lactate dehydrogenase enzyme on the general physiology of the three lactic acid bacteria Lactococcus lactis, Enterococcus faecalis and Streptococcus pyogenes. Surprisingly deletion of the ldh genes hardly affected the growth rate in chemically defined medium, however growth rate was affected in rich medium. Furthermore, deletion of ldh affected the ability for utilization of various ...

The Lactate dehydrogenases (LDH) are key metabolic enzymes in lactic acid bacteria (LAB). The LDH ( E.C. 1.1.1.27) catalyzes the reaction of pyruvate and NADH into lactate and NAD+.We have carried out an experimental and computational study of the effects of fructose-1,6-bisphosphate (FBP), phosphate (Pi) and ionic strength (NaCl concentration) on 3 LDHs from 3 LABs studied at pH 6 and pH 7.