Limits...
The Biokinetic Spectrum for Temperature.

Corkrey R, McMeekin TA, Bowman JP, Ratkowsky DA, Olley J, Ross T - PLoS ONE (2016)

Bottom Line: We found another peak at 67°C and a steady decline in maximum rates thereafter.We used a thermodynamic model to recover the Δ-shape, suggesting that the growth rate limits arise from a trade-off between activity and stability of proteins.The spectrum provides underpinning principles that will find utility in models concerned with the thermal responses of biological processes.

View Article: PubMed Central - PubMed

Affiliation: Tasmanian Institute of Agriculture / School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia.

ABSTRACT
We identify and describe the distribution of temperature-dependent specific growth rates for life on Earth, which we term the biokinetic spectrum for temperature. The spectrum has the potential to provide for more robust modeling in thermal ecology since any conclusions derived from it will be based on observed data rather than using theoretical assumptions. It may also provide constraints for systems biology model predictions and provide insights in physiology. The spectrum has a Δ-shape with a sharp peak at around 42°C. At higher temperatures up to 60°C there was a gap of attenuated growth rates. We found another peak at 67°C and a steady decline in maximum rates thereafter. By using Bayesian quantile regression to summarise and explore the data we were able to conclude that the gap represented an actual biological transition between mesophiles and thermophiles that we term the Mesophile-Thermophile Gap (MTG). We have not identified any organism that grows above the maximum rate of the spectrum. We used a thermodynamic model to recover the Δ-shape, suggesting that the growth rate limits arise from a trade-off between activity and stability of proteins. The spectrum provides underpinning principles that will find utility in models concerned with the thermal responses of biological processes.

No MeSH data available.


Related in: MedlinePlus

Over-plotted fitted growth curves.Over-plotted fitted growth curves from the thermodynamic model for the 694 strains that had at least 5 data points and well defined peaks and with quantile curves for all the 10956 data points. The quantiles are the same as in Fig 2 and are calculated from the observed data. The inset shows the same fitted thermodynamic curves coloured differently for those strains with Topt ≤ 50 or Topt > 50 along with the corresponding quantile curves for each group.
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pone.0153343.g011: Over-plotted fitted growth curves.Over-plotted fitted growth curves from the thermodynamic model for the 694 strains that had at least 5 data points and well defined peaks and with quantile curves for all the 10956 data points. The quantiles are the same as in Fig 2 and are calculated from the observed data. The inset shows the same fitted thermodynamic curves coloured differently for those strains with Topt ≤ 50 or Topt > 50 along with the corresponding quantile curves for each group.

Mentions: To see if we could obtain the overall Δ-shape from the thermodynamic model we began by using it to fit growth curves for all suitable strains. Of the eight distinct thermodynamic parameters four are the main focus of this communication: c, a scaling constant; , the enthalpy of activation (J/mol) of the ‘master reaction’; ΔCP, the heat capacity change on denaturation (J/K mol-amino acid residue) of the rate-controlling enzyme; and n, the number of amino acid residues. Another parameter that canbecalculated from the model is Tmes, the temperature of maximum enzyme stability, at which the putative enzyme in the MRS is least likely to be denatured. We simultaneously fitted growth curves for all suitable strains (Figures 1–44 in S1 File) and calculated their thermodynamic parameters (S1 Table). We show the over-plotted growth curves in Fig 11.


The Biokinetic Spectrum for Temperature.

Corkrey R, McMeekin TA, Bowman JP, Ratkowsky DA, Olley J, Ross T - PLoS ONE (2016)

Over-plotted fitted growth curves.Over-plotted fitted growth curves from the thermodynamic model for the 694 strains that had at least 5 data points and well defined peaks and with quantile curves for all the 10956 data points. The quantiles are the same as in Fig 2 and are calculated from the observed data. The inset shows the same fitted thermodynamic curves coloured differently for those strains with Topt ≤ 50 or Topt > 50 along with the corresponding quantile curves for each group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835062&req=5

pone.0153343.g011: Over-plotted fitted growth curves.Over-plotted fitted growth curves from the thermodynamic model for the 694 strains that had at least 5 data points and well defined peaks and with quantile curves for all the 10956 data points. The quantiles are the same as in Fig 2 and are calculated from the observed data. The inset shows the same fitted thermodynamic curves coloured differently for those strains with Topt ≤ 50 or Topt > 50 along with the corresponding quantile curves for each group.
Mentions: To see if we could obtain the overall Δ-shape from the thermodynamic model we began by using it to fit growth curves for all suitable strains. Of the eight distinct thermodynamic parameters four are the main focus of this communication: c, a scaling constant; , the enthalpy of activation (J/mol) of the ‘master reaction’; ΔCP, the heat capacity change on denaturation (J/K mol-amino acid residue) of the rate-controlling enzyme; and n, the number of amino acid residues. Another parameter that canbecalculated from the model is Tmes, the temperature of maximum enzyme stability, at which the putative enzyme in the MRS is least likely to be denatured. We simultaneously fitted growth curves for all suitable strains (Figures 1–44 in S1 File) and calculated their thermodynamic parameters (S1 Table). We show the over-plotted growth curves in Fig 11.

Bottom Line: We found another peak at 67°C and a steady decline in maximum rates thereafter.We used a thermodynamic model to recover the Δ-shape, suggesting that the growth rate limits arise from a trade-off between activity and stability of proteins.The spectrum provides underpinning principles that will find utility in models concerned with the thermal responses of biological processes.

View Article: PubMed Central - PubMed

Affiliation: Tasmanian Institute of Agriculture / School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia.

ABSTRACT
We identify and describe the distribution of temperature-dependent specific growth rates for life on Earth, which we term the biokinetic spectrum for temperature. The spectrum has the potential to provide for more robust modeling in thermal ecology since any conclusions derived from it will be based on observed data rather than using theoretical assumptions. It may also provide constraints for systems biology model predictions and provide insights in physiology. The spectrum has a Δ-shape with a sharp peak at around 42°C. At higher temperatures up to 60°C there was a gap of attenuated growth rates. We found another peak at 67°C and a steady decline in maximum rates thereafter. By using Bayesian quantile regression to summarise and explore the data we were able to conclude that the gap represented an actual biological transition between mesophiles and thermophiles that we term the Mesophile-Thermophile Gap (MTG). We have not identified any organism that grows above the maximum rate of the spectrum. We used a thermodynamic model to recover the Δ-shape, suggesting that the growth rate limits arise from a trade-off between activity and stability of proteins. The spectrum provides underpinning principles that will find utility in models concerned with the thermal responses of biological processes.

No MeSH data available.


Related in: MedlinePlus