Dynamic metabolomic responses of Escherichia coli to nicotine stress

2014 ◽  
Vol 60 (8) ◽  
pp. 547-556 ◽  
Author(s):  
Lijian Ding ◽  
Juanjuan Chen ◽  
Jianding Zou ◽  
Limin Zhang ◽  
Yangfang Ye
Keyword(s):  
Escherichia Coli ◽  
Metabolic Response ◽  
Tricarboxylic Acid Cycle ◽  
Metabolic Effects ◽  
Acid Fermentation ◽  
Nucleotide Synthesis ◽  
E Coli ◽  
Mixed Acid ◽  
Degrading Bacterium ◽  
Degrading Bacteria

Previously, we reported the metabolic responses of Pseudomonas sp. strain HF-1, a nicotine-degrading bacterium, to nicotine stress. However, the metabolic effects of nicotine on non-nicotine-degrading bacteria that dominate the environment are still unclear. Here, we have used nuclear magnetic resonance based metabolomics in combination with multivariate data analysis methods to comprehensively analyze the metabolic changes in nicotine-treated Escherichia coli. Our results showed that nicotine caused the changes of energy-related metabolism that we believe are due to enhanced glycolysis and mixed acid fermentation as well as inhibited tricarboxylic acid cycle activity. Furthermore, nicotine resulted in the alteration of choline metabolism with a decreased synthesis of betaine but an increased production of dimethylamine. Moreover, nicotine caused a decrease in amino acid concentration and an alteration of nucleotide synthesis. We hypothesize that these changes caused the decrease in bacterial cell density observed in the experiment. These findings provide a comprehensive insight into the metabolic response of E. coli to nicotine stress. Our study highlights the value of metabolomics in elucidating the metabolic mechanisms of nicotine action.

scholarly journals Aerobic Fermentation of d-Glucose by an Evolved Cytochrome Oxidase-Deficient Escherichia coli Strain

2008 ◽  
Vol 74 (24) ◽  
pp. 7561-7569 ◽  
Author(s):  
Vasiliy A. Portnoy ◽  
Markus J. Herrgård ◽  
Bernhard Ø. Palsson
Keyword(s):  
Escherichia Coli ◽  
Oxygen Uptake ◽  
Growth Conditions ◽  
Aerobic Growth ◽  
Acid Fermentation ◽  
Mixed Acid Fermentation ◽  
E Coli ◽  
Knockout Strain ◽  
Mixed Acid ◽  
Cytochrome Oxidases

ABSTRACT Fermentation of glucose to d-lactic acid under aerobic growth conditions by an evolved Escherichia coli mutant deficient in three terminal oxidases is reported in this work. Cytochrome oxidases (cydAB, cyoABCD, and cbdAB) were removed from the E. coli K12 MG1655 genome, resulting in the ECOM3 (E. coli cytochrome oxidase mutant) strain. Removal of cytochrome oxidases reduced the oxygen uptake rate of the knockout strain by nearly 85%. Moreover, the knockout strain was initially incapable of growing on M9 minimal medium. After the ECOM3 strain was subjected to adaptive evolution on glucose M9 medium for 60 days, a growth rate equivalent to that of anaerobic wild-type E. coli was achieved. Our findings demonstrate that three independently adaptively evolved ECOM3 populations acquired different phenotypes: one produced lactate as a sole fermentation product, while the other two strains exhibited a mixed-acid fermentation under oxic growth conditions with lactate remaining as the major product. The homofermenting strain showed a d-lactate yield of 0.8 g/g from glucose. Gene expression and in silico model-based analyses were employed to identify perturbed pathways and explain phenotypic behavior. Significant upregulation of ygiN and sodAB explains the remaining oxygen uptake that was observed in evolved ECOM3 strains. E. coli strains produced in this study showed the ability to produce lactate as a fermentation product from glucose and to undergo mixed-acid fermentation during aerobic growth.

scholarly journals Harnessing Escherichia coli for bio-based production of formate under pressurized H2 and CO2 gases

2021 ◽  
Author(s):  
Magali Roger ◽  
Tom C. Reed ◽  
Frank Sargent
Keyword(s):  
Escherichia Coli ◽  
Carbon Dioxide ◽  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Host Strain ◽  
Acid Fermentation ◽  
E Coli ◽  
Mixed Acid ◽  
Batch Bioreactor ◽  
Growth Deficiency

ABSRACTEscherichia coli is gram-negative bacterium that is a workhorse of the biotechnology industry. The organism has a flexible metabolism and can perform a mixed-acid fermentation under anaerobic conditions. Under these conditions E. coli synthesises a formate hydrogenlyase isoenzyme (FHL-1) that can generate molecular hydrogen and carbon dioxide from formic acid. The reverse reaction is hydrogen-dependent carbon dioxide reduction (HDCR), which has exciting possibilities in bio-based carbon capture and storage if it can be harnessed. In this study, an E. coli host strain was optimised for the production of formate from H2 and CO2 during bacterial growth in a pressurised batch bioreactor. A host strain was engineered that constitutively produced the FHL-1 enzyme and incorporation of tungsten in to the enzyme, in place of molybdenum, helped poise the reaction in the HDCR direction. The engineered E. coli strain showed an ability to grow under fermentative conditions while simultaneously producing formate from gaseous H2 and CO2 supplied in the bioreactor. However, while a sustained pressure of 10 bar N2 had no adverse effect on cell growth, when the culture was placed at or above 4 bar pressure of a H2:CO2 mixture then a clear growth deficiency was observed. Taken together, this work demonstrates that growing cells can be harnessed to hydrogenate carbon dioxide and provides fresh evidence that the FHL-1 enzyme may be intimately linked with bacterial energy metabolism.

scholarly journals Metabolic Engineering ofEscherichia colifor Poly(3-hydroxybutyrate) Production under Microaerobic Condition

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Xiao-Xing Wei ◽  
Wei-Tao Zheng ◽  
Xue Hou ◽  
Jian Liang ◽  
Zheng-Jun Li
Keyword(s):  
Escherichia Coli ◽  
Carbon Metabolism ◽  
Batch Fermentation ◽  
Dry Weight ◽  
Microaerobic Condition ◽  
Acid Fermentation ◽  
Pyruvate Formate Lyase ◽  
E Coli ◽  
Mixed Acid ◽  
Theoretical Yield

The alcohol dehydrogenase promoterPadhEand mixed acid fermentation pathway deficient mutants ofEscherichia coliwere employed to produce poly(3-hydroxybutyrate) (P3HB) under microaerobic condition. TheE. colimutant withackA-pta, poxB, ldhA, andadhEdeletions accumulated 0.67 g/L P3HB, up to 78.84% of cell dry weight in tube cultivation. The deletion of pyruvate formate-lyase genepflBdrastically decreased P3HB production and P3HB content to 0.09 g/L and 24.44%, respectively. OverexpressingpflBvia the plasmid in its knocked out mutant restored cell growth and P3HB accumulation, indicating the importance of the pyruvate formate-lyase in microaerobic carbon metabolism. The engineeredE. coliBWapld (pWYC09) produced 5.00 g/L P3HB from 16.50 g/L glucose in 24 h batch fermentation, and P3HB production yield from glucose was 0.30 g/g, which reached up to 63% of maximal theoretical yield.

Formate and its role in hydrogen production in Escherichia coli

2005 ◽  
Vol 33 (1) ◽  
pp. 42-46 ◽  
Author(s):  
R.G. Sawers
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Production ◽  
Enzyme Complex ◽  
Acid Fermentation ◽  
Mixed Acid Fermentation ◽  
E Coli ◽  
Mixed Acid ◽  
Formate Hydrogenlyase ◽  
Absolute Requirement ◽  
Formate Metabolism

The production of dihydrogen by Escherichia coli and other members of the Enterobacteriaceae is one of the classic features of mixed-acid fermentation. Synthesis of the multicomponent, membrane-associated FHL (formate hydrogenlyase) enzyme complex, which disproportionates formate into CO2 and H2, has an absolute requirement for formate. Formate, therefore, represents a signature molecule in the fermenting E. coli cell and factors that determine formate metabolism control FHL synthesis and consequently dihydrogen evolution.

scholarly journals Hydrogen production in an aerobic environment by Escherichia coli K-12

2022 ◽  
Author(s):  
George D Metcalfe ◽  
Frank Sargent ◽  
Michael Hippler
Keyword(s):  
Escherichia Coli ◽  
Raman Spectroscopy ◽  
Formic Acid ◽  
H2 Production ◽  
Acid Fermentation ◽  
E Coli ◽  
Mixed Acid ◽  
Microaerobic Conditions ◽  
K 12 ◽  
H2 Metabolism

Escherichia coli (E. coli) is a facultative anaerobe that can grow in a variety of environmental conditions. In the complete absence of O2, E. coli can perform a mixed-acid fermentation that contains within it an elaborate metabolism of formic acid. In this study, we use cavity-enhanced Raman spectroscopy (CERS), FTIR, liquid Raman spectroscopy, isotopic labelling, and molecular genetics to make advances in the understanding of bacterial formate and H2 metabolism. It is shown that, under anaerobic conditions, formic acid is generated endogenously, excreted briefly from the cell, and then taken up again to be disproportionated to H2 and CO2 by formate hydrogenlyase (FHL-1). However, exogenously added D-labelled formate behaves quite differently from the endogenous formate and is taken up immediately, independently, and possibly by a different mechanism, by the cell and converted to H2 and CO2. Our data support an anion-proton symport model for formic acid transport. In addition, when E. coli was grown in a microaerobic environment it was possible to analyse aspects of formate and O2 respiration occurring alongside anaerobic metabolism. While cells growing under microaerobic conditions generated endogenous formic acid, no H2 was produced. However, addition of exogenous formate at the outset of cell growth did induce FHL-1 biosynthesis and resulted in formate-dependent H2 production in the presence of O2.

Creation of Plasmidless and Markerless Escherichia coli Succinate Producing Strain and Evaluation of its Biosynthetic Potential during Utilization of Lignocellulosic Sugars

2020 ◽  
Vol 36 (2) ◽  
pp. 3-11
Author(s):  
O.A. Zhuravliova ◽  
Т.А. Voeikova ◽  
A.Yu. Gulevich ◽  
V.G. Debabov
Keyword(s):  
Escherichia Coli ◽  
Succinic Acid ◽  
Plant Biomass ◽  
Anaerobic Fermentation ◽  
Basic Research ◽  
Acid Fermentation ◽  
Mixed Acid ◽  
Gene Coding ◽  
Lignocellulosic Sugars ◽  
Basic Research Project

The plasmidless and markerless Escherichia coli succinate producing strain SGM2.0Pyc-int has been engineered and characterized. The strain has the inactivated main mixed-acid fermentation pathways due to the deletions of ldhA,poxB, ackA,pta, and adhE genes, constitutively expresses the genes of the aceEF-lpdA operon encoding components of pyravate dehydrogenase complex, and possesses the chromosomally integrated Bacillus subtilis pycA gene coding for pyruvate carboxylase. The capacity of the strain to synthesize succinic acid in course of dual-phase aerobic-anaerobic fermentation with lignocellulosic sugars as substrates was studied. The SGM2.0Pyc-int strain synthesized succinic acid from glucose, xylose, and arabinose with a molar yields of 1.41 mol/mol, 1.18 mol/mol, and 1.18 mol/mol, respectively, during the anaerobic production stage. The constructed strain has great potential for developing efficient processes for the succinic acid production from plant biomass-derived sugars. Escherichia coli, fermentation, arabinose, glucose, xylose, succinic acid. The work was supported by a Grant from the Russian Foundation for Basic Research (Project no. 18-29-14005).

scholarly journals Flexible Metabolism and Suppression of Latent Enzymes Are Important forEscherichia coliAdaptation to Diverse Environments within the Host

2019 ◽  
Vol 201 (16) ◽  
Author(s):  
Christopher J. Alteri ◽  
Stephanie D. Himpsl ◽  
Allyson E. Shea ◽  
Harry L. T. Mobley
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Pyruvate Kinase ◽  
Tricarboxylic Acid Cycle ◽  
Financial Burden ◽  
Content Type ◽  
Bacterial Physiology ◽  
E Coli ◽  
Growth Requirements ◽  
Tract Infections

ABSTRACTBacterial metabolism is necessary for adaptation to the host microenvironment. Flexible metabolic pathways allow uropathogenicEscherichia coli(UPEC) to harmlessly reside in the human intestinal tract and cause disease upon extraintestinal colonization.E. coliintestinal colonization requires carbohydrates as a carbon source, while UPEC extraintestinal colonization requires gluconeogenesis and the tricarboxylic acid cycle. UPEC containing disruptions in two irreversible glycolytic steps involving 6-carbon (6-phosphofructokinase;pfkA) and 3-carbon (pyruvate kinase;pykA) substrates have no fitness defect during urinary tract infection (UTI); however, both reactions are catalyzed by isozymes: 6-phosphofructokinases Pfk1 and Pfk2, encoded bypfkAandpfkB, and pyruvate kinases Pyk II and Pyk I, encoded bypykAandpykF. UPEC strains lacking one or both phosphofructokinase-encoding genes (pfkBandpfkA pfkB) and strains lacking one or both pyruvate kinase genes (pykFandpykA pykF) were investigated to determine their regulatory roles in carbon flow during glycolysis by examining their fitness during UTI andin vitrogrowth requirements. Loss of a single phosphofructokinase-encoding gene has no effect on fitness, while thepfkA pfkBdouble mutant outcompeted the parental strain in the bladder. A defect in bladder and kidney colonization was observed with loss ofpykF, while loss ofpykAresulted in a fitness advantage. ThepykA pykFmutant was indistinguishable from wild-typein vivo, suggesting that the presence of Pyk II rather than the loss of Pyk I itself is responsible for the fitness defect in thepykFmutant. These findings suggest thatE. colisuppresses latent enzymes to survive in the host urinary tract.IMPORTANCEUrinary tract infections are the most frequently diagnosed urologic disease, with uropathogenicEscherichia coli(UPEC) infections placing a significant financial burden on the health care system by generating more than two billion dollars in annual costs. This, in combination with steadily increasing antibiotic resistances to present day treatments, necessitates the discovery of new antimicrobial agents to combat these infections. By broadening our scope beyond the study of virulence properties and investigating bacterial physiology and metabolism, we gain a better understanding of how pathogens use nutrients and compete within host microenvironments, enabling us to cultivate new therapeutics to exploit and target pathogen growth requirements in a specific host environment.

Engineering Escherichia coli with acrylate pathway genes for propionic acid synthesis and its impact on mixed-acid fermentation

2012 ◽  
Vol 97 (3) ◽  
pp. 1191-1200 ◽  
Author(s):  
Vijayalakshmi Kandasamy ◽  
Hema Vaidyanathan ◽  
Ivana Djurdjevic ◽  
Elamparithi Jayamani ◽  
K. B. Ramachandran ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Propionic Acid ◽  
Acid Synthesis ◽  
Acid Fermentation ◽  
Mixed Acid Fermentation ◽  
Mixed Acid ◽  
Acrylate Pathway

scholarly journals Cofactor Engineering: a Novel Approach to Metabolic Engineering in Lactococcus lactis by Controlled Expression of NADH Oxidase

1998 ◽  
Vol 180 (15) ◽  
pp. 3804-3808 ◽  
Author(s):  
Felix Lopez de Felipe ◽  
Michiel Kleerebezem ◽  
Willem M. de Vos ◽  
Jeroen Hugenholtz
Keyword(s):  
Lactococcus Lactis ◽  
Oxidase Activity ◽  
Nadh Oxidase ◽  
Metabolic Effects ◽  
Initial Growth ◽  
Acid Fermentation ◽  
Aerobic Conditions ◽  
Mixed Acid Fermentation ◽  
Mixed Acid ◽  
Nadh Oxidase Activity

ABSTRACT NADH oxidase-overproducing Lactococcus lactis strains were constructed by cloning the Streptococcus mutans nox-2gene, which encodes the H2O-forming NADH oxidase, on the plasmid vector pNZ8020 under the control of the L. lactis nisA promoter. This engineered system allowed a nisin-controlled 150-fold overproduction of NADH oxidase at pH 7.0, resulting in decreased NADH/NAD ratios under aerobic conditions. Deliberate variations on NADH oxidase activity provoked a shift from homolactic to mixed-acid fermentation during aerobic glucose catabolism. The magnitude of this shift was directly dependent on the level of NADH oxidase overproduced. At an initial growth pH of 6.0, smaller amounts of nisin were required to optimize NADH oxidase overproduction, but maximum NADH oxidase activity was twofold lower than that found at pH 7.0. Nonetheless at the highest induction levels, levels of pyruvate flux redistribution were almost identical at both initial pH values. Pyruvate was mostly converted to acetoin or diacetyl via α-acetolactate synthase instead of lactate and was not converted to acetate due to flux limitation through pyruvate dehydrogenase. The activity of the overproduced NADH oxidase could be increased with exogenously added flavin adenine dinucleotide. Under these conditions, lactate production was completely absent. Lactate dehydrogenase remained active under all conditions, indicating that the observed metabolic effects were only due to removal of the reduced cofactor. These results indicate that the observed shift from homolactic to mixed-acid fermentation under aerobic conditions is mainly modulated by the level of NADH oxidation resulting in low NADH/NAD+ratios in the cells.

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