Experimental determination of control of glycolysis in Lactococcus lactis

Koebmann, Brian J.; Andersen, Heidi Winterberg; Solem, Christian; Jensen, Peter Ruhdal

doi:10.1007/978-94-017-2029-8_14

Cited by 31 publications

(49 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This was confirmed experimentally for Pfkp (72)(73)(74) which is consistent with our own findings. However, Pyk1p was found to exert a significant level of control over both the rate and direction of carbon flux in yeast during growth on glucose (73), as well as in Lactococcus lactis (75). Accordingly, the Pyk1p-1310 isoform was found significantly associated with CO 2 flux in our study.…”

Section: Discussionsupporting

confidence: 42%

Linking Post-Translational Modifications and Variation of Phenotypic Traits

Albertin

Marullo

Bely

et al. 2013

Molecular & Cellular Proteomics

View full text Add to dashboard Cite

Enzymes can be post-translationally modified, leading to isoforms with different properties. The phenotypic consequences of the quantitative variability of isoforms have never been studied. We used quantitative proteomics to dissect the relationships between the abundances of the enzymes and isoforms of alcoholic fermentation, metabolic traits, and growth-related traits in Saccharomyces cerevisiae. Although the enzymatic pool allocated to the fermentation proteome was constant over the culture media and the strains considered, there was variation in abundance of individual enzymes and sometimes much more of their isoforms, which suggests the existence of selective constraints on total protein abundance and trade-offs between isoforms. Variations in abundance of some isoforms were significantly associated to metabolic traits and growth-related traits. In particular, cell size and maximum population size were highly correlated to the degree of N-terminal acetylation of the alcohol dehydrogenase. The fermentation proteome was found to be shaped by human selection, through the differential targeting of a few isoforms for each food-processing origin of strains. These results highlight the importance of posttranslational modifications in the diversity of metabolic and life-history traits. Molecular & Cellular Proteomics 12: 10.1074/mcp.M112.024349, 720 -735, 2013.The key problem in understanding genotype-phenotype relationships is the complexity arising from multiple levels of cellular functioning. Among them, metabolic networks involve series of interconnected chemical reactions catalyzed by enzymes, allowing the transformation of input substrates into intermediate or final metabolites. These networks play an essential role in an organism's growth, reproduction, and ability to maintain cell integrity and to respond to environmental changes (1, 2). The metabolic fluxes, as well as the metabolite concentrations, are governed by the activity of the enzymes, which depends on three types of factors: kinetic parameters, enzyme abundance, and activation state of the enzyme. The kinetic parameters are determined by the sequence and the three-dimensional structure of the protein (3). The abundance of the enzymes is the result of numerous molecular processes taking place from the transcriptional to the translational level, including epigenetic modifications of the DNA and chromatin (4), transcriptional regulation by transcription factors (5), mRNA capping and splicing and small RNA regulation (6), protein turnover (7), etc. The enzyme activation state is primarily because of post-translational modifications of the native protein, themselves highly regulated (8, 9). Other mechanisms involved in enzyme activity are proteinprotein interactions and allosteric regulation, such mechanisms being sometimes mediated through post-translational modifications (10, 11). The resulting isoforms can display differences in activity, affinity for partners (protein or effectors), and stability (12). The most studied modification is the reversibl...

show abstract

Section: Discussionsupporting

confidence: 42%

Linking Post-Translational Modifications and Variation of Phenotypic Traits

Albertin

Marullo

Bely

et al. 2013

Molecular & Cellular Proteomics

View full text Add to dashboard Cite

show abstract

“…In contrast, GAPDH of L. lactis MG1363 was shown to control the flux only when the enzyme level was less than 25% of the wild-type level (48). When the expression levels of phosphofructokinase, pyruvate kinase, and LDH were modulated individually in L. lactis MG 1363, none of these enzymes was found to limit the glycolytic flux, and it was therefore concluded that the control most likely is distributed over several steps (28). The levels of glycolytic enzymes have been shown to be highly conserved when the cells go from the growing state to the resting state (40) (29) or an ionophore has been added (this study) indicate that ADP and ATP are involved in the regulation.…”

Section: Discussionmentioning

confidence: 95%

“…Low glycolytic flux has commonly been ascribed to be the cause of mixed acid product formation (15,16,28,48). Indeed, during batch growth on maltose, trehalose, and galactose, the glycolytic fluxes are lower than those during growth on glucose (30,47,50).…”

Section: Discussionmentioning

confidence: 99%

The Pool of ADP and ATP Regulates Anaerobic Product Formation in Resting Cells of Lactococcus lactis

Palmfeldt

Paese

Hahn‐Hägerdal

et al. 2004

Appl Environ Microbiol

View full text Add to dashboard Cite

Lactococcus lactis grows homofermentatively on glucose, while its growth on maltose under anaerobic conditions results in mixed acid product formation in which formate, acetate, and ethanol are formed in addition to lactate. Maltose was used as a carbon source to study mixed acid product formation as a function of the growth rate. In batch and nitrogen-limited chemostat cultures mixed acid product formation was shown to be linked to the growth rate, and homolactic fermentation occurred only in resting cells. Two of the four lactococcal strains investigated with maltose, L. lactis 65.1 and MG1363, showed more pronounced mixed acid product formation during growth than L. lactis ATCC 19435 or IL-1403. In resting cell experiments all four strains exhibited homolactic fermentation. In resting cells the intracellular concentrations of ADP, ATP, and fructose 1,6-bisphosphate were increased and the concentration of P i was decreased compared with the concentrations in growing cells. Addition of an ionophore (monensin or valinomycin) to resting cultures of L. lactis 65.1 induced mixed acid product formation concomitant with decreases in the ADP, ATP, and fructose 1,6-bisphosphate concentrations. ADP and ATP were shown to inhibit glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, and alcohol dehydrogenase in vitro. Alcohol dehydrogenase was the most sensitive enzyme and was totally inhibited at an adenine nucleotide concentration of 16 mM, which is close to the sum of the intracellular concentrations of ADP and ATP of resting cells. This inhibition of alcohol dehydrogenase might be partially responsible for the homolactic behavior of resting cells. A hypothesis regarding the level of the ATP-ADP pool as a regulating mechanism for the glycolytic flux and product formation in L. lactis is discussed.Lactococcus lactis is a lactic acid bacterium that is used as a starter culture in the dairy industry. L. lactis has a rather simple and well-characterized metabolism and converts sugars mainly into lactic acid. In recent years L. lactis has also been evaluated as organism for production of industrial lactic acid (23, 38) and has been subjected to metabolic engineering to reroute its metabolism towards novel products (13,18,22,25,26). To take full advantage of bacterial processes, it is very important to understand which intracellular and extracellular factors influence the metabolic rate and product formation. L. lactis is an attractive model organism for studies of glycolysis and pyruvate metabolism, since oxidative phosphorylation normally does not occur and more than 90% of the carbon source is recovered as fermentation by-products, mainly lactate. In glycolysis glyceraldehyde-3-phosphate dehydrogenase (GAPDH) converts NAD ϩ to NADH, which must be regenerated for continued carbon catabolism. Lactate dehydrogenase (LDH) regenerates NAD ϩ by converting the end product of glycolysis, pyruvate, to lactate. An alternative way for lactococci to regenerate NAD ϩ is by production of ethanol by alcohol dehydrogenase (ADH...

show abstract

“…lactis is by far the best-studied lactic acid bacterium (3,13,14,23,24,30), and a kinetic model for its complete glycolysis, including some branching pathways, has been developed (2, 10). For the other two lactic acid bacteria, less information is readily available.…”

mentioning

confidence: 99%

Characterization of Three Lactic Acid Bacteria and Their Isogenic ldh Deletion Mutants Shows Optimization for Y _ATP (Cell Mass Produced per Mole of ATP) at Their Physiological pHs

Fiedler

Bekker

Jönsson

et al. 2011

Appl Environ Microbiol

View full text Add to dashboard Cite

Several lactic acid bacteria use homolactic acid fermentation for generation of ATP. Here we studied the role of the lactate dehydrogenase enzyme on the general physiology of the three homolactic acid bacteria Lactococcus lactis, Enterococcus faecalis, and Streptococcus pyogenes. Of note, deletion of the ldh genes hardly affected the growth rate in chemically defined medium under microaerophilic conditions. However, the growth rate was affected in rich medium. Furthermore, deletion of ldh affected the ability for utilization of various substrates as a carbon source. A switch to mixed acid fermentation was observed during glucose-limited continuous growth and was dependent on the growth rate for S. pyogenes and on the pH for E. faecalis. In S. pyogenes and L. lactis, a change in pH resulted in a clear change in Y ATP (cell mass produced per mole of ATP). The pH that showed the highest Y ATP corresponded to the pH of the natural habitat of the organisms.Comparative analyses, as demonstrated by comparative genomics and bioinformatics, are extremely powerful for (i) transfer of information from (experimentally) well-studied organisms to other organisms and (ii) when coupled to functional and phenotypic information, insight into the relative importance of components to the observed differences and similarities. The central principle is that important aspects of the functional differences between organisms derive not only from the differences in genetic components (which underlies comparative genomics) but also from the interactions between their components. Although this type of analysis is much discussed, only a very few studies focus on cross-species comparisons.Here we study three relatively simple and highly related lactic acid bacteria (LAB) which nevertheless exhibit stark and important differences in their functional relationship with humans: these organisms are homofermentative lactic acid bacteria, namely, Lactococcus lactis, the major microorganism used in the dairy industry (21); Enterococcus faecalis, a major LAB in the human intestinal microbiota and a (fecal) contaminant in food and water as well as a contributor to food fermentation (16); and Streptococcus pyogenes, an important human pathogen (9, 15). These organisms have a similar primary metabolism but persist in completely different environments (milk, feces, skin/mucous membranes/blood).L. lactis is by far the best-studied lactic acid bacterium (3,13,14,23,24,30), and a kinetic model for its complete glycolysis, including some branching pathways, has been developed (2, 10). For the other two lactic acid bacteria, less information is readily available.Generally, observations made with L. lactis are quickly translated to other LAB. With this approach we are able to separate organism-specific observations from observations that are general for LAB.Here three LAB and their isogenic ldh deletion strains were characterized with respect to growth rates, catabolic flux distribution, ATP demand, and their ability to utilize different carbon sources. Our da...

show abstract

Experimental determination of control of glycolysis in Lactococcus lactis

Cited by 31 publications

References 30 publications

Linking Post-Translational Modifications and Variation of Phenotypic Traits

Linking Post-Translational Modifications and Variation of Phenotypic Traits

The Pool of ADP and ATP Regulates Anaerobic Product Formation in Resting Cells of Lactococcus lactis

Characterization of Three Lactic Acid Bacteria and Their Isogenic ldh Deletion Mutants Shows Optimization for Y _ATP (Cell Mass Produced per Mole of ATP) at Their Physiological pHs

Contact Info

Product

Resources

About

Experimental determination of control of glycolysis in Lactococcus lactis

Cited by 31 publications

References 30 publications

Linking Post-Translational Modifications and Variation of Phenotypic Traits

Linking Post-Translational Modifications and Variation of Phenotypic Traits

The Pool of ADP and ATP Regulates Anaerobic Product Formation in Resting Cells of Lactococcus lactis

Characterization of Three Lactic Acid Bacteria and Their Isogenic ldh Deletion Mutants Shows Optimization for Y ATP (Cell Mass Produced per Mole of ATP) at Their Physiological pHs

Contact Info

Product

Resources

About

Characterization of Three Lactic Acid Bacteria and Their Isogenic ldh Deletion Mutants Shows Optimization for Y _ATP (Cell Mass Produced per Mole of ATP) at Their Physiological pHs