scholarly journals Glucose transport of Escherichia coli growing in glucose-limited continuous culture

1979 ◽  
Vol 178 (1) ◽  
pp. 97-101 ◽  
Author(s):  
I S Hunter ◽  
H L Kornberg
Keyword(s):  
Escherichia Coli ◽  
Continuous Culture ◽  
Glucose Concentration ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Glucose Limitation ◽  
Low Glucose ◽  
Rate Limiting ◽  
Excess Glucose ◽  
Stimulation Of

Dilute cultures of wild-type Escherichia coli K12 and of derivatives impaired in one or other Enzyme-II component of the glucose phosphotransferase system were grown in continuous culture under glucose limitation. Cells harvested from the chemostat took up [U-14C]glucose from 0.1 mM solutions at rates directly related to the rates at which those cells had grown; the activity of the phosphotransferase system in those cells, rendered permeable with optimal accounts of toluene, parallels the ability of the cells to take up glucose. The capacity of these systems was rate-limiting for growth under the negligibly low glucose concentration in the chemostat, but was adequate to account for the stimulation of respiration observed when the cells were presented suddenly with excess glucose.

scholarly journals Glucose transport as rate-limiting step in the growth of Escherichia coli on glucose

1976 ◽  
Vol 156 (2) ◽  
pp. 477-480 ◽  
Author(s):  
D Herbert ◽  
H L Kornberg
Keyword(s):  
Escherichia Coli ◽  
Continuous Culture ◽  
Glucose Transport ◽  
Growth Rates ◽  
Glucose Limitation ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Wide Range ◽  
Rate Limiting

Over a wide range of growth rates, two strains of Escherichia coli growing aerobically in continuous culture under glucose limitation utilized glucose at rates identical with those at which cells harvested from the chemostats transported [14C]glucose.

scholarly journals Mutational Adaptation of Escherichia coli to Glucose Limitation Involves Distinct Evolutionary Pathways in Aerobic and Oxygen-Limited Environments

Genetics ◽  
1999 ◽  
Vol 153 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Karen Manché ◽  
Lucinda Notley-McRobb ◽  
Thomas Ferenci
Keyword(s):  
Escherichia Coli ◽  
Clonal Diversity ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Glucose Limitation ◽  
E Coli ◽  
Uptake Pathway ◽  
Evolutionary Pathways ◽  
The Difference ◽  
K 12

Abstract Mutational adaptations leading to improved glucose transport were followed with Escherichia coli K-12 growing in glucose-limited continuous cultures. When populations were oxygen limited as well as glucose limited, all bacteria within 280 generations contained mutations in a single codon of the ptsG gene. V12F and V12G replacements in the enzyme IIBCGlc component of the glucose phosphotransferase system were responsible for improved transport. In stark contrast, ptsG mutations were uncommon in fully aerobic glucose-limited cultures, in which polygenic mutations in mgl, mlc, and malT (regulating an alternate high-affinity Mgl/LamB uptake pathway) spread through the adapted population. Hence the same organism adapted to the same selection (glucose limitation) by different evolutionary pathways depending on a secondary environmental factor. The clonal diversity in the adapted populations was also significantly different. The PtsG V12F substitution under O2 limitation contributed to a universal “winner clone” whereas polygenic, multiallelic changes led to considerable polymorphism in aerobic cultures. Why the difference in adaptive outcomes? E. coli physiology prevented scavenging by the LamB/Mgl system under O2 limitation; hence, ptsG mutations provided the only adaptive pathway. But ptsG mutations in aerobic cultures are overtaken by mgl, mlc, and malT adaptations with better glucose-scavenging ability. Indeed, when an mglA::Tn10 mutant with an inactivated Mgl/LamB pathway was introduced into two independent aerobic chemostats, adaptation of the Mgl– strain involved the identical ptsG mutation found under O2-limited conditions with wild-type or Mgl– bacteria.

Involvement of the cgtA gene function in stimulation of DNA repair in Escherichia coli and Vibrio harveyi

Microbiology ◽  
2003 ◽  
Vol 149 (7) ◽  
pp. 1763-1770 ◽  
Author(s):  
Ryszard Zielke ◽  
Aleksandra Sikora ◽  
Rafał Dutkiewicz ◽  
Grzegorz Wegrzyn ◽  
Agata Czyż
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Dna Repair ◽  
Gene Product ◽  
Uv Irradiation ◽  
Vibrio Harveyi ◽  
Bacterial Species ◽  
Wild Type ◽  
E Coli ◽  
Stimulation Of

CgtA is a member of the Obg/Gtp1 subfamily of small GTP-binding proteins. CgtA homologues have been found in various prokaryotic and eukaryotic organisms, ranging from bacteria to humans. Nevertheless, despite the fact that cgtA is an essential gene in most bacterial species, its function in the regulation of cellular processes is largely unknown. Here it has been demonstrated that in two bacterial species, Escherichia coli and Vibrio harveyi, the cgtA gene product enhances survival of cells after UV irradiation. Expression of the cgtA gene was found to be enhanced after UV irradiation of both E. coli and V. harveyi. Moderate overexpression of cgtA resulted in higher UV resistance of E. coli wild-type and dnaQ strains, but not in uvrA, uvrB, umuC and recA mutant hosts. Overexpression of the E. coli recA gene in the V. harveyi cgtA mutant, which is very sensitive to UV light, restored the level of survival of UV-irradiated cells to the levels observed for wild-type bacteria. Moreover, the basal level of the RecA protein was lower in a temperature-sensitive cgtA mutant of E. coli than in the cgtA + strain, and contrary to wild-type bacteria, no significant increase in recA gene expression was observed after UV irradiation of this cgtA mutant. Finally, stimulation of uvrB gene transcription under these conditions was impaired in the V. harveyi cgtA mutant. All these results strongly suggest that the cgtA gene product is involved in DNA repair processes, most probably by stimulation of recA gene expression and resultant activation of RecA-dependent DNA repair pathways.

scholarly journals Synthesis of GDP-Mannose and Mannosylglycerate from Labeled Mannose by Genetically Engineered Escherichia coli without Loss of Specific Isotopic Enrichment

2003 ◽  
Vol 69 (1) ◽  
pp. 233-240 ◽  
Author(s):  
Maria-Manuel Sampaio ◽  
Helena Santos ◽  
Winfried Boos
Keyword(s):  
Escherichia Coli ◽  
Cold Water ◽  
Genetically Engineered ◽  
Isotopic Enrichment ◽  
Rhodothermus Marinus ◽  
Phosphotransferase System ◽  
Gene Encoding ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

ABSTRACT We report the construction of an Escherichia coli mutant that harbors two compatible plasmids and that is able to synthesize labeled 2-O-α-d-mannosyl-d-glycerate from externally added labeled mannose without the loss of specific isotopic enrichment. The strain carries a deletion in the manA gene, encoding phosphomannose isomerase. This deletion prevents the formation of fructose-6-phosphate from mannose-6-phosphate after the uptake of mannose from the medium by mannose-specific enzyme II of the phosphotransferase system (PtsM). The strain also has a deletion of the cps gene cluster that prevents the synthesis of colanic acid, a mannose-containing polymer. Plasmid-encoded phosphomannomutase (cpsG) and mannose-1-phosphate guanylyltransferase (cpsB) ensure the formation of GDP-mannose. A second plasmid harbors msg, a gene from Rhodothermus marinus that encodes mannosylglycerate synthase, which catalyzes the formation of 2-O-α-d-mannosyl-d-glycerate from GDP-mannose and endogenous glycerate. The rate-limiting step in 2-O-α-d-mannosyl-d-glycerate formation is the transfer of GDP-mannose to glycerate. 2-O-α-d-mannosyl-d-glycerate can be released from cells by treatment with cold-water shock. The final product is formed in a yield exceeding 50% the initial quantity of labeled mannose, including loss during preparation and paper chromatography.

scholarly journals Alterations in Protein Expression Caused by thehha Mutation in Escherichia coli: Influence of Growth Medium Osmolarity

1999 ◽  
Vol 181 (10) ◽  
pp. 3018-3024 ◽  
Author(s):  
Carlos Balsalobre ◽  
Jörgen Johansson ◽  
Bernt Eric Uhlin ◽  
Antonio Juárez ◽  
Francisco J. Muñoa
Keyword(s):  
Escherichia Coli ◽  
Growth Medium ◽  
Gel Electrophoresis ◽  
Catabolite Repression ◽  
Protein Pattern ◽  
Polyacrylamide Gel Electrophoresis ◽  
Wild Type ◽  
Phosphotransferase System ◽  
New Family ◽  
Medium Osmolarity

ABSTRACT The Hha protein belongs to a new family of regulators involved in the environmental regulation of virulence factors. The aim of this work was to study the effect of the hha mutation on the overall protein pattern of Escherichia coli cells by two-dimensional polyacrylamide gel electrophoresis. The growth medium osmolarity clearly influenced the effect of the hhamutation. The number of proteins whose expression was altered inhha cells, compared with wild-type cells, was three times larger at a high osmolarity than at a low osmolarity. Among the proteins whose expression was modified by the hha allele, both OmpA and protein IIAGlc of the phosphotransferase system could be identified. As this latter enzyme participates in the regulation of the synthesis of cyclic AMP and hence influences the catabolite repression system, we tested whether the expression of thelacZ gene was also modified in hha mutants. This was the case, suggesting that at least some of the pleiotropic effects of the hha mutation could be caused by its effect on the catabolite repression system.

scholarly journals Identification of a Phosphotransferase System of Escherichia coli Required for Growth on N-Acetylmuramic Acid

2004 ◽  
Vol 186 (8) ◽  
pp. 2385-2392 ◽  
Author(s):  
Ulrike Dahl ◽  
Tina Jaeger ◽  
Bao Trâm Nguyen ◽  
Julia M. Sattler ◽  
Christoph Mayer
Keyword(s):  
Escherichia Coli ◽  
Energy Analysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sole Source ◽  
Wild Type ◽  
Phosphotransferase System ◽  
E Coli ◽  
Glucose Transport System ◽  
Single Polypeptide

ABSTRACT We report here that wild-type Escherichia coli grows on N-acetylmuramic acid (MurNAc) as the sole source of carbon and energy. Analysis of mutants defective in N-acetylglucosamine (GlcNAc) catabolism revealed that the catabolic pathway for MurNAc merges into the GlcNAc pathway on the level of GlcNAc 6-phosphate. Furthermore, analysis of mutants defective in components of the phosphotransferase system (PTS) revealed that a PTS is essential for growth on MurNAc. However, neither the glucose-, mannose/glucosamine-, nor GlcNAc-specific PTS (PtsG, ManXYZ, and NagE, respectively) was found to be necessary. Instead, we identified a gene at 55 min on the E. coli chromosome that is responsible for MurNAc uptake and growth. It encodes a single polypeptide consisting of the EIIB and C domains of a so-far-uncharacterized PTS that was named murP. MurP lacks an EIIA domain and was found to require the activity of the crr-encoded enzyme IIA-glucose (EIIAGlc), a component of the major glucose transport system for growth on MurNAc. murP deletion mutants were unable to grow on MurNAc as the sole source of carbon; however, growth was rescued by providing murP in trans expressed from an isopropylthiogalactopyranoside-inducible plasmid. A functional His6 fusion of MurP was constructed, isolated from membranes, and identified as a polypeptide with an apparent molecular mass of 37 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis. Close homologs of MurP were identified in the genome of several bacteria, and we believe that these organisms might also be able to utilize MurNAc.

scholarly journals Why Does Escherichia coli Grow More Slowly on Glucosamine than on N-Acetylglucosamine? Effects of Enzyme Levels and Allosteric Activation of GlcN6P Deaminase (NagB) on Growth Rates

2005 ◽  
Vol 187 (9) ◽  
pp. 2974-2982 ◽  
Author(s):  
Laura I. Álvarez-Añorve ◽  
Mario L. Calcagno ◽  
Jacqueline Plumbridge
Keyword(s):  
Escherichia Coli ◽  
Growth Rates ◽  
Sugar Transport ◽  
Point Mutations ◽  
Sole Source ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Allosteric Activation

ABSTRACT Wild-type Escherichia coli grows more slowly on glucosamine (GlcN) than on N-acetylglucosamine (GlcNAc) as a sole source of carbon. Both sugars are transported by the phosphotransferase system, and their 6-phospho derivatives are produced. The subsequent catabolism of the sugars requires the allosteric enzyme glucosamine-6-phosphate (GlcN6P) deaminase, which is encoded by nagB, and degradation of GlcNAc also requires the nagA-encoded enzyme, N-acetylglucosamine-6-phosphate (GlcNAc6P) deacetylase. We investigated various factors which could affect growth on GlcN and GlcNAc, including the rate of GlcN uptake, the level of induction of the nag operon, and differential allosteric activation of GlcN6P deaminase. We found that for strains carrying a wild-type deaminase (nagB) gene, increasing the level of the NagB protein or the rate of GlcN uptake increased the growth rate, which showed that both enzyme induction and sugar transport were limiting. A set of point mutations in nagB that are known to affect the allosteric behavior of GlcN6P deaminase in vitro were transferred to the nagB gene on the Escherichia coli chromosome, and their effects on the growth rates were measured. Mutants in which the substrate-induced positive cooperativity of NagB was reduced or abolished grew even more slowly on GlcN than on GlcNAc or did not grow at all on GlcN. Increasing the amount of the deaminase by using a nagC or nagA mutation to derepress the nag operon improved growth. For some mutants, a nagA mutation, which caused the accumulation of the allosteric activator GlcNAc6P and permitted allosteric activation, had a stronger effect than nagC. The effects of the mutations on growth in vivo are discussed in light of their in vitro kinetics.

scholarly journals Effects of Overexpression of Nutrient Receptors on Germination of Spores of Bacillus subtilis

2003 ◽  
Vol 185 (8) ◽  
pp. 2457-2464 ◽  
Author(s):  
Rosa-Martha Cabrera-Martinez ◽  
Federico Tovar-Rojo ◽  
Venkata Ramana Vepachedu ◽  
Peter Setlow
Keyword(s):  
Bacillus Subtilis ◽  
Spore Germination ◽  
Maximum Rate ◽  
Additional Component ◽  
Wild Type ◽  
Rate Limiting ◽  
Very High ◽  
Stimulation Of

ABSTRACT The rates of germination of Bacillus subtilis spores with l-alanine were increased markedly, in particular at low l-alanine concentrations, by overexpression of the tricistronic gerA operon that encodes the spore's germinant receptor for l-alanine but not by overexpression of gerA operon homologs encoding receptors for other germinants. However, spores with elevated levels of the GerA proteins did not germinate more rapidly in a mixture of asparagine, glucose, fructose, and K+ (AGFK), a germinant combination that requires the participation of at least the germinant receptors encoded by the tricistronic gerB and gerK operons. Overexpression of the gerB or gerK operon or both the gerB and gerK operons also did not stimulate spore germination in AGFK. Overexpression of a mutant gerB operon, termed gerB*, that encodes a receptor allowing spore germination in response to either d-alanine or l-asparagine also caused faster spore germination with these germinants, again with the largest enhancement of spore germination rates at lower germinant concentrations. However, the magnitudes of the increases in the germination rates with d-alanine or l-asparagine in spores overexpressing gerB* were well below the increases in the spore's levels of the GerBA protein. Germination of gerB* spores with d-alanine or l-asparagine did not require participation of the products of the gerK operon, but germination with these agents was decreased markedly in spores also overexpressing gerA. These findings suggest that (i) increases in the levels of germinant receptors that respond to single germinants can increase spore germination rates significantly; (ii) there is some maximum rate of spore germination above which stimulation of GerA operon receptors alone will not further increase the rate of spore germination, as action of some protein other than the germinant receptors can become rate limiting; (iii) while previous work has shown that the wild-type GerB and GerK receptors interact in some fashion to cause spore germination in AGFK, there also appears to be an additional component required for AGFK-triggered spore germination; (iv) activation of the GerB receptor with d-alanine or l-asparagine can trigger spore germination independently of the GerK receptor; and (v) it is likely that the different germinant receptors interact directly and/or compete with each other for some additional component needed for initiation of spore germination. We also found that very high levels of overexpression of the gerA or gerK operon (but not the gerB or gerB* operon) in the forespore blocked sporulation shortly after the engulfment stage, although sporulation appeared normal with the lower levels of gerA or gerK overexpression that were used to generate spores for analysis of rates of germination.

Sign in / Sign up

Export Citation Format

Share Document