Modified carbon flux during oxygen limited growth of Corynebacterium glutamicum and the consequences for amino acid overproduction

1993 ◽  
Vol 15 (5) ◽  
pp. 449-454 ◽  
Author(s):  
H Dominguez ◽  
C Nezondet ◽  
N D Lindley ◽  
M Cocaign
Keyword(s):  
Amino Acid ◽  
Corynebacterium Glutamicum ◽  
Carbon Flux ◽  
Limited Growth

Optimal Ratio of Carbon Flux between Glycolysis and the Pentose Phosphate Pathway for Amino Acid Accumulation in Corynebacterium glutamicum

2020 ◽  
Vol 9 (7) ◽  
pp. 1615-1622
Author(s):  
Katsuki Murai ◽  
Daisuke Sasaki ◽  
Shunsuke Kobayashi ◽  
Akira Yamaguchi ◽  
Hiroto Uchikura ◽  
...  
Keyword(s):  
Amino Acid ◽  
Corynebacterium Glutamicum ◽  
Pentose Phosphate Pathway ◽  
Carbon Flux ◽  
Pentose Phosphate ◽  
Optimal Ratio ◽  
Acid Accumulation ◽  
Amino Acid Accumulation

scholarly journals Kog1/Raptor mediates metabolic rewiring during nutrient limitation by controlling SNF1/AMPK activity

2021 ◽  
Vol 7 (16) ◽  
pp. eabe5544
Author(s):  
Zeenat Rashida ◽  
Rajalakshmi Srinivasan ◽  
Meghana Cyanam ◽  
Sunil Laxman
Keyword(s):  
Amino Acid ◽  
Nutrient Limitation ◽  
Carbon Flux ◽  
Metabolic Flux ◽  
Carbon Allocation ◽  
Carbon Utilization ◽  
Acid Biosynthesis ◽  
Control Growth ◽  
Ampk Activity ◽  
Delayed Growth

In changing environments, cells modulate resource budgeting through distinct metabolic routes to control growth. Accordingly, the TORC1 and SNF1/AMPK pathways operate contrastingly in nutrient replete or limited environments to maintain homeostasis. The functions of TORC1 under glucose and amino acid limitation are relatively unknown. We identified a modified form of the yeast TORC1 component Kog1/Raptor, which exhibits delayed growth exclusively during glucose and amino acid limitations. Using this, we found a necessary function for Kog1 in these conditions where TORC1 kinase activity is undetectable. Metabolic flux and transcriptome analysis revealed that Kog1 controls SNF1-dependent carbon flux apportioning between glutamate/amino acid biosynthesis and gluconeogenesis. Kog1 regulates SNF1/AMPK activity and outputs and mediates a rapamycin-independent activation of the SNF1 targets Mig1 and Cat8. This enables effective glucose derepression, gluconeogenesis activation, and carbon allocation through different pathways. Therefore, Kog1 centrally regulates metabolic homeostasis and carbon utilization during nutrient limitation by managing SNF1 activity.

scholarly journals Amino acid limited growth of starter cultures in milk

1987 ◽  
Vol 45 (4) ◽  
pp. 191-198 ◽  
Author(s):  
J. Hugenholtz ◽  
M. Dijkstra ◽  
H. Veldkamp
Keyword(s):  
Amino Acid ◽  
Starter Cultures ◽  
Limited Growth

scholarly journals Identification of glyA (Encoding Serine Hydroxymethyltransferase) and Its Use Together with the Exporter ThrE To Increase l-Threonine Accumulation by Corynebacterium glutamicum

2002 ◽  
Vol 68 (7) ◽  
pp. 3321-3327 ◽  
Author(s):  
Petra Simic ◽  
Juliane Willuhn ◽  
Hermann Sahm ◽  
Lothar Eggeling
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Corynebacterium Glutamicum ◽  
Serine Hydroxymethyltransferase ◽  
Acid Formation ◽  
Initial Activity ◽  
Intracellular Degradation ◽  
Cleavage Activity ◽  
Substrate Reduction

ABSTRACT l-Threonine can be made by the amino acid-producing bacterium Corynebacterium glutamicum. However, in the course of this process, some of the l-threonine is degraded to glycine. We detected an aldole cleavage activity of l-threonine in crude extracts with an activity of 2.2 nmol min−1 (mg of protein)−1. In order to discover the molecular reason for this activity, we cloned glyA, encoding serine hydroxymethyltransferase (SHMT). By using affinity-tagged glyA, SHMT was isolated and its substrate specificity was determined. The aldole cleavage activity of purified SHMT with l-threonine as the substrate was 1.3 μmol min−1 (mg of protein)−1, which was 4% of that with l-serine as substrate. Reduction of SHMT activity in vivo was obtained by placing the essential glyA gene in the chromosome under the control of P tac , making glyA expression isopropylthiogalactopyranoside dependent. In this way, the SHMT activity in an l-threonine producer was reduced to 8% of the initial activity, which led to a 41% reduction in glycine, while l-threonine was simultaneously increased by 49%. The intracellular availability of l-threonine to aldole cleavage was also reduced by overexpressing the l-threonine exporter thrE. In C. glutamicum DR-17, which overexpresses thrE, accumulation of 67 mM instead of 49 mM l-threonine was obtained. This shows that the potential for amino acid formation can be considerably improved by reducing its intracellular degradation and increasing its export.

scholarly journals PII Signal Transduction Protein GlnK Alleviates Feedback Inhibition of N-Acetyl-L-Glutamate Kinase by L-Arginine in Corynebacterium glutamicum

2020 ◽  
Vol 86 (8) ◽  
Author(s):  
Meijuan Xu ◽  
Mi Tang ◽  
Jiamin Chen ◽  
Taowei Yang ◽  
Xian Zhang ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Corynebacterium Glutamicum ◽  
Feedback Inhibition ◽  
Amino Acid Biosynthesis ◽  
Arginine Biosynthesis ◽  
Acid Biosynthesis ◽  
Content Type ◽  
Pii Protein

ABSTRACT PII signal transduction proteins are ubiquitous and highly conserved in bacteria, archaea, and plants and play key roles in controlling nitrogen metabolism. However, research on biological functions and regulatory targets of PII proteins remains limited. Here, we illustrated experimentally that the PII protein Corynebacterium glutamicum GlnK (CgGlnK) increased l-arginine yield when glnK was overexpressed in Corynebacterium glutamicum. Data showed that CgGlnK regulated l-arginine biosynthesis by upregulating the expression of genes of the l-arginine metabolic pathway and interacting with N-acetyl-l-glutamate kinase (CgNAGK), the rate-limiting enzyme in l-arginine biosynthesis. Further assays indicated that CgGlnK contributed to alleviation of the feedback inhibition of CgNAGK caused by l-arginine. In silico analysis of the binding interface of CgGlnK-CgNAGK suggested that the B and T loops of CgGlnK mainly interacted with C and N domains of CgNAGK. Moreover, F11, R47, and K85 of CgGlnK were identified as crucial binding sites that interact with CgNAGK via hydrophobic interaction and H bonds, and these interactions probably had a positive effect on maintaining the stability of the complex. Collectively, this study reveals PII-NAGK interaction in nonphotosynthetic microorganisms and further provides insights into the regulatory mechanism of PII on amino acid biosynthesis in corynebacteria. IMPORTANCE Corynebacteria are safe industrial producers of diverse amino acids, including l-glutamic acid and l-arginine. In this study, we showed that PII protein GlnK played an important role in l-glutamic acid and l-arginine biosynthesis in C. glutamicum. Through clarifying the molecular mechanism of CgGlnK in l-arginine biosynthesis, the novel interaction between CgGlnK and CgNAGK was revealed. The alleviation of l-arginine inhibition of CgNAGK reached approximately 48.21% by CgGlnK addition, and the semi-inhibition constant of CgNAGK increased 1.4-fold. Furthermore, overexpression of glnK in a high-yield l-arginine-producing strain and fermentation of the recombinant strain in a 5-liter bioreactor led to a remarkably increased production of l-arginine, 49.978 g/liter, which was about 22.61% higher than that of the initial strain. In conclusion, this study provides a new strategy for modifying amino acid biosynthesis in C. glutamicum.

Regulative interactions of the osmosensing C-terminal domain in the trimeric glycine betaine transporter BetP from Corynebacterium glutamicum

2009 ◽  
Vol 390 (8) ◽  
Author(s):  
Reinhard Krämer ◽  
Christine Ziegler
Keyword(s):  
Amino Acid ◽  
Corynebacterium Glutamicum ◽  
Protein Interactions ◽  
Regulation Mechanism ◽  
Protein Protein Interactions ◽  
Molecular Switching ◽  
X Ray ◽  
X Ray Crystallography ◽  
Terminal Domain ◽  
Domain Reorientation

Abstract Activation of the osmoregulated trimeric betaine transporter BetP from Corynebacterium glutamicum was shown to depend mainly on the correct folding and integrity of its 55 amino acid long, partly α-helical C-terminal domain. Reorientation of the three C-terminal domains in the BetP trimer indicates different lipid-protein and protein-protein interactions of the C-terminal domain during osmoregulation. A regulation mechanism is suggested where this domain switches the transporter from the inactive to the active state. Interpretation of recently obtained electron and X-ray crystallography data of BetP led to a structure-function based model of C-terminal molecular switching involved in osmoregulation.

scholarly journals Carbon-flux distribution in the central metabolic pathways of Corynebacterium glutamicum during growth on fructose

1998 ◽  
Vol 254 (1) ◽  
pp. 96-102 ◽  
Author(s):  
Helene Dominguez ◽  
Catherine Rollin ◽  
Armel Guyonvarch ◽  
Jean-Luc Guerquin-Kern ◽  
Muriel Cocaign-Bousquet ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Metabolic Pathways ◽  
Carbon Flux ◽  
Flux Distribution ◽  
Carbon Flux Distribution
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