Cation Movements at Alkaline pH in Bacteria Growing Without Respiration

Kobayashi, Hiroshi; Saito, Hiromi; Futatsugi, Lui; Kakegawa, Tomohito

doi:10.1002/9780470515631.ch15

Cited by 5 publications

(3 citation statements)

References 39 publications

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“…2001), and these may work at neutral pH instead of OmpC and OmpF. Thus, our present results support the previous proposal that different systems are used under different pH conditions (Kobayashi et al. 1999, 2000).…”

Section: Discussionsupporting

confidence: 91%

OmpC and OmpF are required for growth under hyperosmotic stress above pH 8 in Escherichia coli

Kaeriyama

Machida

Kitakaze

et al. 2006

Lett Appl Microbiol

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Aims: To investigate the requirement of outer membrane porins for osmotic adaptation at alkaline pH in Escherichia coli. Methods and Results: Escherichia coli mutants deficient in ompC, ompF and both genes were constructed and the growth of these mutants was observed at alkaline pH. The growth rate of the mutant deficient in both ompC and ompF was slower than that of the wild type and mutants deficient in one of these genes under hyperosmotic stress at pHs above 8·0. The decreased rate was recovered when a cloned ompC was introduced to the mutant, but the growth recovery with a cloned ompF was partial. Such growth diminution was not observed at pHs below 8·0. Conclusion: OmpC and OmpF were shown to participate in hyperosmotic adaptation at alkaline pH in E. coli. Significance and Impact of the Study: This study is the first report to demonstrate that OmpC and OmpF are required for hyperosmotic adaptation at pHs above 8·0, but not below 8·0.

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Section: Discussionsupporting

confidence: 91%

OmpC and OmpF are required for growth under hyperosmotic stress above pH 8 in Escherichia coli

Kaeriyama

Machida

Kitakaze

et al. 2006

Lett Appl Microbiol

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“…While the intracellular pH values of bacteria grown in alkaline environments are generally more acidic than their extracellular environment (3), at a pH above 8.0, Enterococcus hirae does not appear to possess a system that maintains a constant intracellular pH (17). Many factors could potentially contribute to the tolerance of alkaline pH found in enterococci, including activation of specific proton pumps, and specific enzymatic systems and/or buffering devices that help to keep the internal pH constant.…”

Section: Discussionmentioning

confidence: 99%

Effects of prolonged exposure to alkaline pH on Enterococcus faecalis survival and specific gene transcripts

Appelbe¹,

Sedgley²

2007

Oral Microbiology and Immunology

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“…From an in vivo perspective, although the intracellular pH of microbes growing in particularly acidic or basic environments may not be equal to that of the external environment, the internal pH is influenced by that of the environment (Salhaney et al ., 1975; Cook et al ., 1996; Wiegel, 1998). Also, because the values of intracellular pH vary for different organisms that are actively producing ATP (Imai & Ohno, 1995; Kobayashi et al ., 1999), differences in pH must be taken into account when determining which species are the most prevalent in a solution. Other ambiguities arise from the fact that all cells contain appreciable concentrations of metal cations, such as Mg 2+ , Ca 2+ , Na + , and K + that complex with the highly charged anionic ADP and ATP species that predominate in a solution at the pH and ionic strengths prevailing in cells (Smith et al ., 1991).…”

Section: Coupling Electron Flow and Atp Synthesismentioning

confidence: 99%

Quantifying the energetics of metabolic reactions in diverse biogeochemical systems: electron flow and ATP synthesis

LaRowe¹,

Helgeson²

2007

Geobiology

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Classical solution chemistry and thermodynamics have been used to quantify the energetics of two fundamental bioenergetic processes over a range of environmental conditions in which life is known to thrive: (1) the flow of electrons originating from an electron donor through the nicotinamide adenine dinucleotide (NAD) redox couple to an electron acceptor, and (2) the synthesis of ATP from ADP and aqueous phosphate. The approach taken explicitly accounts for the chemical formulas, charge states, complexation of ADP and ATP with magnesium, and the thermodynamic properties of individual biochemical species in stoichiometric and charge‐balanced reactions among biomolecules and other compounds. Because these species are represented in the reactions by explicit formula units, the chemical and thermodynamic consequences of the reactions can be evaluated as a function of temperature, pH, and bulk composition. To illustrate the utility of this approach, the energetics of the oxidation of glucose and hydrogen and the reduction of oxygen and sulfate coupled to NAD were characterized as functions of pH and temperature. The thermodynamic drive (chemical affinity, A) for glucose to reduce NAD increases as the temperature increases, whereas the opposite is true for hydrogen. Also, at lower pHs, the chemical affinity is lower for these two electron donors to reduce NAD than at higher pHs. Similarly, the chemical affinity for oxidation of NAD by oxygen decreases by more than 2 kcal mol−1 as temperature increases from 0 to 125 °C but the chemical affinity for oxidation of NAD by sulfate decreases by less than 1 kcal mol−1. Calculations were also carried out to quantify the energetics of the synthesis of ATP for different bulk compositions, pHs, and temperatures. The chemical affinity for the synthesis of MgATP from MgADP and aqueous monophosphate at pH 5 minimizes with increasing temperature from 0 to 125 °C, which is not the case at pH 7 or 9. The procedures employed in these various calculations can be used to better understand how different environmental variables influence biogeochemical interactions. In addition, they help constrain the minimum energy required to sustain a particular microbial population and provide the means to determine why certain types of metabolism occur in the environments in which they do.

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Cation Movements at Alkaline pH in Bacteria Growing Without Respiration

Cited by 5 publications

References 39 publications

OmpC and OmpF are required for growth under hyperosmotic stress above pH 8 in Escherichia coli

OmpC and OmpF are required for growth under hyperosmotic stress above pH 8 in Escherichia coli

Effects of prolonged exposure to alkaline pH on Enterococcus faecalis survival and specific gene transcripts

Quantifying the energetics of metabolic reactions in diverse biogeochemical systems: electron flow and ATP synthesis

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