Regulation of glucose metabolism in bacterial systems

Doelle, Horst W.; Ewings, Ken N.; Hollywood, N.

doi:10.1007/3540116982_1

Cited by 63 publications

(44 citation statements)

References 151 publications

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“…Under anaerobic conditions, glycolytic enzymes and reductases such as lactate dehydrogenase (Ldh) and alcohol dehydrogenase (Adh) are present at higher levels than under aerobic conditions (Doelle et al, 1982). Consistently, we determined lower in vitro activities of Pfk, Pyk, and Adh in bioconversions with the control strain harvested from aerobic cultures (Table II), compared to previous experiments with the control strain harvested from anaerobic cultures (Emmerling et al, 1999).…”

Section: Influence Of Preharvest Physiology On Carbon Flux In Restingsupporting

confidence: 67%

Altered regulation of pyruvate kinase or co-overexpression of phosphofructokinase increases glycolytic fluxes in restingEscherichia coli

Emmerling

Bailey

Sauer

2000

Biotechnol. Bioeng.

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Glycolytic fluxes in resting Escherichia coli were enhanced by overexpression of heterologous pyruvate kinases (Pyk) from Bacillus stearothermophilus and Zymomonas mobilis, but not homologous Pyk. Compared to the control, an increase of 10% in specific glucose consumption and of 15% in specific ethanol production rates was found in anaerobic resting cells, expressing the heterologous Pyks, that were harvested from exponentially growing aerobic cultures. A further increase in glycolytic flux was achieved by simultaneous overexpression of E. coli phosphofructokinase (Pfk) and Pyk with specific glucose consumption and ethanol production rates of 25% and 35% greater, respectively, than the control. Fluxes to lactate were not significantly affected, contrary to previous observations with resting cells harvested from anaerobically growing cultures. To correlate the physiology of resting cells with the physiology of cells prior to harvest, we determined the relevant growth parameters from aerobic and anaerobic precultures. We conclude that glycolytic fluxes in E. coli with submaximal (aerobic) metabolic activity can be increased by overexpression of pyruvate kinases which do not require allosteric activation or co‐overexpression with Pfk. However, such improvements require more extensive engineering in E. coli with near maximal (anaerobic) metabolic activity. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 67: 623–627, 2000.

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Section: Influence Of Preharvest Physiology On Carbon Flux In Restingsupporting

confidence: 67%

Altered regulation of pyruvate kinase or co-overexpression of phosphofructokinase increases glycolytic fluxes in restingEscherichia coli

Emmerling

Bailey

Sauer

2000

Biotechnol. Bioeng.

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“…All attribute acetate formation either to limitations in respiratory NADH turnover and concomitant ATP generation through oxidative phosphorylation (Andersen & von Meyenburg, 1980;Doelle et al, 1982;Reiling et al, 1985;Varma & Palsson, 1994) or to initial limitations in the TCA cycle (Majewski & Domach, 1990;Han et al, 1992). Moreover, Han et al (1992) concluded that these limitations cause a reorganization of the catabolic flux distribution to meet the anabolic demands at high growth rates by generating the necessary amount of energy by using both oxidative metabolism and acetic acid formation.…”

Section: Discussionmentioning

confidence: 99%

Metabolic flux analysis of Escherichia coli in glucose-limited continuous culture. I. Growth-rate-dependent metabolic efficiency at steady state

Kayser¹,

Weber²,

Hecht³

et al. 2005

Microbiology

167

170

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The Escherichia coli K-12 strain TG1 was grown at 28 6C in aerobic glucose-limited continuous cultures at dilution rates ranging from 0?044 to 0?415 h "1 . The rates of biomass formation, the specific rates of glucose, ammonium and oxygen uptake and the specific carbon dioxide evolution rate increased linearly with the dilution rate up to 0?3 h "1 . At dilution rates between 0?3 h "1 and 0?4 h "1 , a strong deviation from the linear increase to lower specific oxygen uptake and carbon dioxide evolution rates occurred. The biomass formation rate and the specific glucose and ammonium uptake rates did not deviate that strongly from the linear increase up to dilution rates of 0?4 h "1 . An increasing percentage of glucose carbon flow towards biomass determined by a reactor mass balance and a decreasing specific ATP production rate concomitant with a decreasing adenylate energy charge indicated higher energetic efficiency of carbon substrate utilization at higher dilution rates. Estimation of metabolic fluxes by a stoichiometric model revealed an increasing activity of the pentose phosphate pathway and a decreasing tricarboxylic acid cycle activity with increasing dilution rates, indicative of the increased NADPH and precursor demand for anabolic purposes at the expense of ATP formation through catabolic activities. Thus, increasing growth rates first result in a more energy-efficient use of the carbon substrate for biomass production, i.e. a lower portion of the carbon substrate is channelled into the respiratory, energy-generating pathway. At dilution rates above 0?4 h "1 , close to the wash-out point, respiration rates dropped sharply and accumulation of glucose and acetic acid was observed. Energy generation through acetate formation yields less ATP compared with complete oxidation of the sugar carbon substrate, but is the result of maximized energy generation under conditions of restrictions in the tricarboxylic acid cycle or in respiratory NADH turnover. Thus, the data strongly support the conclusion that, in aerobic glucose-limited continuous cultures of E. coli TG1, two different carbon limitations occur: at low dilution rates, cell growth is limited by cell-carbon supply and, at high dilution rates, by energy-carbon supply.

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“…Thus, acetate excretion occurs anaerobically during mixed-acid fermentation (54). It also occurs aerobically when growth on excess glucose (or other highly assimilable carbon sources) inhibits respiration (195,196), a behavior called the bacterial Crabtree effect (98,119,280,379). As a consequence of the Crabtree effect, as much as 15% of the glucose can be excreted as acetate (196).…”

Section: Why Cells Excrete Acetatementioning

confidence: 99%

The Acetate Switch

Wolfe

2005

Microbiol Mol Biol Rev

1,082

1,274

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To succeed, many cells must alternate between life-styles that permit rapid growth in the presence of abundant nutrients and ones that enhance survival in the absence of those nutrients. One such change in life-style, the “acetate switch,” occurs as cells deplete their environment of acetate-producing carbon sources and begin to rely on their ability to scavenge for acetate. This review explains why, when, and how cells excrete or dissimilate acetate. The central components of the “switch” (phosphotransacetylase [PTA], acetate kinase [ACK], and AMP-forming acetyl coenzyme A synthetase [AMP-ACS]) and the behavior of cells that lack these components are introduced. Acetyl phosphate (acetyl∼P), the high-energy intermediate of acetate dissimilation, is discussed, and conditions that influence its intracellular concentration are described. Evidence is provided that acetyl∼P influences cellular processes from organelle biogenesis to cell cycle regulation and from biofilm development to pathogenesis. The merits of each mechanism proposed to explain the interaction of acetyl∼P with two-component signal transduction pathways are addressed. A short list of enzymes that generate acetyl∼P by PTA-ACKA-independent mechanisms is introduced and discussed briefly. Attention is then directed to the mechanisms used by cells to “flip the switch,” the induction and activation of the acetate-scavenging AMP-ACS. First, evidence is presented that nucleoid proteins orchestrate a progression of distinct nucleoprotein complexes to ensure proper transcription of its gene. Next, the way in which cells regulate AMP-ACS activity through reversible acetylation is described. Finally, the “acetate switch” as it exists in selected eubacteria, archaea, and eukaryotes, including humans, is described

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Regulation of glucose metabolism in bacterial systems

Cited by 63 publications

References 151 publications

Altered regulation of pyruvate kinase or co-overexpression of phosphofructokinase increases glycolytic fluxes in restingEscherichia coli

Altered regulation of pyruvate kinase or co-overexpression of phosphofructokinase increases glycolytic fluxes in restingEscherichia coli

Metabolic flux analysis of Escherichia coli in glucose-limited continuous culture. I. Growth-rate-dependent metabolic efficiency at steady state

The Acetate Switch

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