Selection for biomass production based on respiration parameters in eucalypts: acclimation of growth and respiration to changing growth temperature

1996 ◽  
Vol 26 (9) ◽  
pp. 1569-1576 ◽  
Author(s):  
R.S. Criddle ◽  
T.S. Anekonda ◽  
R.M. Sachs ◽  
R.W. Breidenbach ◽  
L.D. Hansen
Keyword(s):  
Growth Rate ◽  
Biomass Production ◽  
Growth Temperature ◽  
Growth Rates ◽  
Heat Rate ◽  
Metabolic Rates ◽  
Different Temperatures ◽  
Controlled Environments ◽  
Respiration Parameters

This paper examines the relation between respiratory physiology and growth rate and the effects of environment on this relation for the purpose of developing means for accelerating and improving selection of trees for biomass production. The relations among biomass production, respiratory metabolism, and growth temperature in controlled environments were determined for three Eucalyptus genotypes (clones). Eucalyptuscamaldulensis 4016, E. camaldulensis C11, and Eucalyptusgundal (Eucalyptusgunnii × Eucalyptusdalrympleana hybrid) GD1 were selected for this study because of known qualitative differences in their field growth responses to temperature. These clones were grown in controlled environments at three temperatures. Measurements were made of growth rate, metabolic heat rate, and dark CO2 production rate for plants grown at each of the three temperatures. This allowed determination of respiration rates of plants originally adapted for growth in different climates, but acclimated during growth at three different controlled temperatures, and also determination of respiration changes resulting from short-term changes in temperature. Growth rates of the three clones differed in their patterns of response to changes in growth temperature. For example, C11 grew most rapidly at the highest temperature, while GD1 was slowest at high temperature. Metabolic rates and the temperature dependence of metabolic rates of the clones differed and the pattern of differences changed when plants became acclimated to growth at different temperatures. Changes in metabolic properties of the three clones with growth and measurement temperatures are consistent with the growth rate changes. In general, increased growth rate was accompanied by increased respiration rate measured either as heat rate or as rate of CO2 production. Growth rates were inversely related to two measures of metabolic energy use efficiency. Growth rates decreased as values of heat loss per gram dry weight produced and values of heat loss per mole of CO2 produced increased. Recognition of these relations between growth rate and respiration parameters at different temperatures in controlled environement may allow prediction of relative growth rate performance of Eucalyptus clones over a range of growth climates.

scholarly journals Determination of In Situ Bacterial Growth Rates in Aquifers and Aquifer Sediments

2003 ◽  
Vol 69 (7) ◽  
pp. 3798-3808 ◽  
Author(s):  
Brian J. Mailloux ◽  
Mark E. Fuller
Keyword(s):  
Growth Rate ◽  
Fluorescence Intensity ◽  
Growth Rates ◽  
Direct Determination ◽  
Shallow Aquifer ◽  
Cell Counting ◽  
Field Scale ◽  
Doubling Times

ABSTRACT Laboratory and field-scale studies with stained cells were performed to monitor cell growth in groundwater systems. During cell division, the fluorescence intensity of the protein stain 5-(and 6-)-carboxyfluorescein diacetate succinimidyl ester (CFDA/SE) for each cell is halved, and the intensity can be tracked with a flow cytometer. Two strains of bacteria, Comamonas sp. strain DA001 and Acidovorax sp. strain OY-107, both isolated from a shallow aquifer, were utilized in this study. The change in the average generation or the average fluorescence intensity of the CFDA/SE-stained cells could be used to obtain estimates of doubling times. In microcosm experiments, the CFDA/SE-based doubling times were similar to the values calculated by total cell counting and were independent of cell concentration. Intact and repacked sediment core experiments with the same bacteria indicated that changes in groundwater chemistry were just as important as growth rates in determining planktonic cell concentrations. The growth rates within the sediment cores were similar to those calculated in microcosm experiments, and preferential transport of the daughter cells was not observed. The experiments indicated that the growth rates could be determined in systems with cell losses due to other phenomena, such as attachment to sediment or predation. Application of this growth rate estimation method to data from a field-scale bacterial transport experiment indicated that the doubling time was approximately 15 days, which is the first known direct determination of an in situ growth rate for bacteria in an aquifer.

scholarly journals Determination of the in situ growth rate of Microcystis based on carbon and nitrogen stable isotope fractionation

2017 ◽  
Vol 18 (3) ◽  
pp. 984-993 ◽  
Author(s):  
Shucong Zhen ◽  
Wei Zhu
Keyword(s):  
Growth Rate ◽  
Stable Isotope ◽  
Growth Rates ◽  
Isotope Fractionation ◽  
Taihu Lake ◽  
Nitrogen Stable Isotope ◽  
Average Growth ◽  
Carbon And Nitrogen ◽  
Stable Isotope Fractionation

Abstract Stable isotope fractionation of carbon and nitrogen in algal cells can be affected by photosynthesis, temperature, nutrient and CO2 concentrations, and cell size. As a consequence, carbon and nitrogen stable isotope techniques are not popular for determining algal growth rates. To counter these issues, this study used BG11 medium to cultivate Microcystis in the laboratory. First, the carbon and nitrogen stable isotope values of the culture medium and the algae are determined. Then, based on changes in isotope fractionation before and after cell division, a function μ = 1.32(1 + x)−0.52 relating growth rate and stable isotope fractionation is established. By substituting stable isotope values from Taihu Lake water and Microcystis into this function, the growth rate of the Microcystis in Taihu Lake is calculated to be 0.64 d−1 in May and 0.12 d−1 in September, with an average growth rate of 0.42 d−1. By incorporating most of the above-mentioned factors influencing isotope fractionation, this method can determine the growth rate of algae based directly on the stable isotope fractionation relationship, enabling simple and practical determination of algae growth rates.

Optimal growth temperature hypothesis: Why do anchovy flourish and sardine collapse or vice versa under the same ocean regime?

2007 ◽  
Vol 64 (5) ◽  
pp. 768-776 ◽  
Author(s):  
Akinori Takasuka ◽  
Yoshioki Oozeki ◽  
Ichiro Aoki
Keyword(s):  
Growth Rate ◽  
Growth Temperature ◽  
Growth Rates ◽  
Synergistic Effects ◽  
Larval Growth ◽  
Optimal Growth ◽  
Regime Shifts ◽  
Optimal Growth Temperature ◽  
Sea Temperature ◽  
Japanese Sardine

The out-of-phase population oscillations between anchovy and sardine have been attributed to climate changes. However, the biological processes causing these species alternations have remained unresolved. Here we propose a simple "optimal growth temperature" hypothesis, in which anchovy and sardine regime shifts are caused by differential optimal temperatures for growth rates during the early life stages. Dome-shaped relationships between growth rate and sea temperature were detected for both Japanese anchovy (Engraulis japonicus) and Japanese sardine (Sardinops melanostictus) larvae based on otolith microstructure analysis. The optimal growth rate for anchovy larvae occurred at 22.0 °C, whereas that for sardine larvae occurred at 16.2 °C. Ambient temperatures have historically fluctuated between these optima, which could lead to contrasting fluctuations in larval growth rates between the two species. This simple mechanism could potentially cause the shifts between the warm anchovy regime and the cool sardine regime in the western North Pacific. Although retrospective analysis suggested synergistic effects of other factors (e.g., trophic interactions and fishing), the optimal growth temperature concept would provide a possible biological mechanism of anchovy and sardine regime shifts.

Prediction of long-term growth rates of larch clones by calorimetric measurement of metabolic heat rates

1989 ◽  
Vol 19 (5) ◽  
pp. 606-611 ◽  
Author(s):  
L. D. Hansen ◽  
E. A. Lewis ◽  
D. J. Eatough ◽  
D. P. Fowler ◽  
R. S. Criddle
Keyword(s):  
Linear Correlation ◽  
Growth Rates ◽  
Room Temperature ◽  
Growth Stage ◽  
Heat Rate ◽  
Metabolic Rates ◽  
Calorimetric Measurement ◽  
Metabolic Heat ◽  
Metabolic Heat Rate

A linear correlation exists between long-term growth rates and calorimetrically measured metabolic heat rates in some clones of larch (Larixlaricina (Du Roi) K. Koch). The metabolic heat rate per gram of tissue was found to be highly variable among clones from different trees and reproducible for clones of the same tree. The ordering of metabolic rates for clones was shown to be independent of the physiological growth stage in which the measurements were made. Winter-hardened tissue was found to be immediately active on warming to room temperature.

The Effect of Phosphine Pressure on the Band Gap of Ga0.5In0.5P

1994 ◽  
Vol 340 ◽  
Author(s):  
Sarah R. Kurtz ◽  
D. J. Arent ◽  
K. A. Bertness ◽  
J. M. Olson
Keyword(s):  
Growth Rate ◽  
Surface Structure ◽  
Band Gap ◽  
Surface Diffusion ◽  
Parameter Space ◽  
Growth Temperature ◽  
Growth Rates ◽  
Diffusion Length ◽  
Group V ◽  
Group Iii

ABSTRACTThe band gap of Ga0.51n0.5P is studied as a function of phosphine pressure, B-type substrate misorientation, growth rate, and growth temperature, with emphasis placed on the effect of the phosphine pressure. Over most of the parameter space explored (high temperatures, large substrate misorientations, and low growth rates), the band gap increases with decreasing phosphine. This increase is proposed to be caused by lower phosphorus coverage of the surface, resulting in a different surface structure that doesn't promote ordering. The implications of this effect on the observed variations of band gap with growth temperature, substrate misorientation, and growth rate are discussed. For regions of parameter space in which the ordering appears to be kinetically limited by surface diffusion, the band gap increases slightly with phosphine pressure, consistent with observations that increased group-V pressure decreases the group-III surface diffusion length.

Approach to Assessment of Corrosion Growth in Pipelines

2002 ◽  
Author(s):  
Bill Gu ◽  
Richard Kania ◽  
Sandeep Sharma ◽  
Ming Gao
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Assessment Tool ◽  
Accurate Determination ◽  
Soil Drainage ◽  
Corrosion Condition ◽  
Preliminary Corrosion ◽  
Corrosion Defects ◽  
Growth Assessment

Two key components of corrosion growth assessment in pipelines are accurate determination of corrosion growth rate and application of corrosion growth to future integrity of a pipeline. PII has developed a corrosion growth assessment tool, Run Comparison (RunCom) software that allows accurate determination of corrosion growth. RunCom compares the raw signals of the same defect present in two inspection runs to report the real active corrosion defects and their growth with less error. Since variations in corrosion growth along the pipeline can be significant, a single value of average or maximum corrosion growth rate does not represent the corrosion condition of the pipeline and could result in a conservative or non-conservative conclusion for future integrity. PII introduces a Decision Tree Analysis method to categorize the corroded regions along the pipeline and calculate the mean corrosion growth rates in these specific areas. Relationships between corrosion growth rate and defect geometry are also identified. The influence of soil, drainage, and topography on corrosion rates is examined to determine representative corrosion growth rates along the pipeline. A systematic approach incorporating statistical analysis with mechanistic understanding of corrosion for preliminary corrosion assessment of pipeline systems is discussed.

scholarly journals The number of active metabolic pathways is bounded by the number of cellular constraints at maximal metabolic rates

2017 ◽  
Author(s):  
Daan H. de Groot ◽  
Coco van Boxtel ◽  
Robert Planqué ◽  
Frank J. Bruggeman ◽  
Bas Teusink
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Metabolic Pathways ◽  
Extremum Principle ◽  
Overflow Metabolism ◽  
Large Network ◽  
Metabolic Rates ◽  
Enzyme Expression ◽  
Membrane Area ◽  
Metabolic Flux Distribution

AbstractGrowth rate is a near-universal selective pressure across microbial species. High growth rates require hundreds of metabolic enzymes, each with different nonlinear kinetics, to be precisely tuned within the bounds set by physicochemical constraints. Yet, the metabolic behaviour of many species is characterized by simple relations between growth rate, enzyme expression levels and metabolic rates. We asked if this simplicity could be the outcome of optimisation by evolution. Indeed, when the growth rate is maximized –in a static environment under mass-conservation and enzyme expression constraints– we prove mathematically that the resulting optimal metabolic flux distribution is described by a limited number of subnetworks, known as Elementary Flux Modes (EFMs). We show that, because EFMs are the minimal subnetworks leading to growth, a small active number automatically leads to the simple relations that are measured. We find that the maximal number of flux-carrying EFMs is determined only by the number of imposed constraints on enzyme expression, not by the size, kinetics or topology of the network. This minimal-EFM extremum principle is illustrated in a graphical framework, which explains qualitative changes in microbial behaviours, such as overflow metabolism and co-consumption, and provides a method for identification of the enzyme expression constraints that limit growth under the prevalent conditions. The extremum principle applies to all microorganisms that are selected for maximal growth rates under protein concentration constraints, for example the solvent capacities of cytosol, membrane or periplasmic space.Author summaryThe microbial genome encodes for a large network of enzyme-catalyzed reactions. The reaction rates depend on concentrations of enzymes and metabolites, which in turn depend on those rates. Cells face a number of biophysical constraints on enzyme expression, for example due to a limited membrane area or cytosolic volume. Considering this complexity and nonlinearity of metabolism, how is it possible, that experimental data can often be described by simple linear models? We show that it is evolution itself that selects for simplicity. When reproductive rate is maximised, the number of active independent metabolic pathways is bounded by the number of growth-limiting enzyme constraints, which is typically small. A small number of pathways automatically generates the measured simple relations. We identify the importance of growth-limiting constraints in shaping microbial behaviour, by focussing on their mechanistic nature. We demonstrate that overflow metabolism – an important phenomenon in bacteria, yeasts, and cancer cells – is caused by two constraints on enzyme expression. We derive experimental guidelines for constraint identification in microorganisms. Knowing these constraints leads to increased understanding of metabolism, and thereby to better predictions and more effective manipulations.

scholarly journals Increased Biomass Production by Mesophilic Food-Associated Bacteria through Lowering the Growth Temperature from 30°C to 10°C

2016 ◽  
Vol 82 (13) ◽  
pp. 3754-3764 ◽  
Author(s):  
Waldemar Seel ◽  
Julia Derichs ◽  
André Lipski
Keyword(s):  
Growth Rate ◽  
Cell Count ◽  
Protein Content ◽  
Biomass Production ◽  
Growth Temperature ◽  
Content Type ◽  
Biomass Formation ◽  
Defined Media ◽  
Density And Biomass ◽  
Reference Strains

ABSTRACTFive isolates from chilled food and refrigerator inner surfaces and closely related reference strains of the speciesEscherichia coli,Listeria monocytogenes,Staphylococcus xylosus,Bacillus cereus,Pedobacter nutrimenti, andPedobacter panaciterraewere tested for the effect of growth temperature (30°C and 10°C) on biomass formation. Growth was monitored via optical density, and biomass formation was measured at the early stationary phase based on the following parameters in complex and defined media: viable cell count, total cell count, cell dry weight, whole-cell protein content, and cell morphology. According to the lack of growth at 1°C, all strains were assigned to the thermal class of mesophiles. Glucose and ammonium consumption related to cell yield were analyzed in defined media. Except for the protein content, temperature had a significant (ttest,P< 0.05) effect on all biomass formation parameters for each strain. The results show a significant difference between the isolates and the related reference strains. Isolates achieved an increase in biomass production between 20% and 110% at the 10°C temperature, which is 15 to 25°C lower than their maximum growth rate temperatures. In contrast, reference strains showed a maximum increase of only about 25%, and some reference strains showed no increase or a decrease of approximately 25%. As expected, growth rates for all strains were higher at 30°C than at 10°C, while biomass production for isolates was higher at 10°C than at 30°C. In contrast, the reference strains showed similar growth yields at the two temperatures. This also demonstrates for mesophilic bacterial strains more efficient nutrient assimilation during growth at low temperatures. Until now, this characteristic was attributed only to psychrophilic microorganisms.IMPORTANCEFor several psychrophilic species, increased biomass formation was described at temperatures lower than optimum growth temperatures, which are defined by the highest growth rate. This work shows increased biomass formation at low growth temperatures for mesophilic isolates. A comparison with closely related reference strains from culture collections showed a significantly smaller increase or no increase in biomass formation. This indicates a loss of specific adaptive mechanisms (e.g., cold adaptation) for mesophiles during long-term cultivation. The increased biomass production for mesophiles under low-temperature conditions opens new avenues for a more efficient biotechnological transformation of nutrients to microbial biomass. These findings may also be important for risk assessment of cooled foods since risk potential is often correlated with the cell numbers present in food samples.

scholarly journals Modelling the growth rate of Listeria monocytogenes in cooked ham stored at different temperatures

2017 ◽  
Vol 61 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Jacek Szczawiński ◽  
Małgorzata Ewa Szczawińska ◽  
Adriana Łobacz ◽  
Michał Tracz ◽  
Agnieszka Jackowska-Tracz
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Goodness Of Fit ◽  
Storage Temperature ◽  
Growth Curves ◽  
Information Criterion ◽  
Model Fit ◽  
Bacteria Growth ◽  
Cooked Ham ◽  
Different Temperatures

AbstractIntroduction:The purpose of the study was to determine and model the growth rates ofL. monocytogenesin cooked cured ham stored at various temperatures.Material and Methods:Samples of cured ham were artificially contaminated with a mixture of threeL. monocytogenesstrains and stored at 3, 6, 9, 12, or 15°C for 16 days. The number of listeriae was determined after 0, 1, 2, 3, 5, 7, 9, 12, 14, and 16 days. A series of decimal dilutions were prepared from each sample and plated onto ALOA agar, after which the plates were incubated at 37°C for 48 h under aerobic conditions. The bacterial counts were logarithmised and analysed statistically. Five repetitions of the experiment were performed.Results:Both storage temperature and time were found to significantly influence the growth rate of listeriae (P < 0.01). The test bacteria growth curves were fitted to three primary models: the Gompertz, Baranyi, and logistic. The mean square error (MSE) and Akaike’s information criterion (AIC) were calculated to evaluate the goodness of fit. It transpired that the logistic model fit the experimental data best. The natural logarithms ofL. monocytogenes’mean growth rates from this model were fitted to two secondary models: the square root and polynomial.Conclusion:Modelling in both secondary types can predict the growth rates ofL. monocytogenesin cooked cured ham stored at each studied temperature, but mathematical validation showed the polynomial model to be more accurate.

Transition from Grey to White and White to Grey in Fe-C-X Eutectic Alloys

1984 ◽  
Vol 34 ◽  
Author(s):  
P. Magnin ◽  
W. Kurz
Keyword(s):  
Growth Rate ◽  
Directional Solidification ◽  
Growth Rates ◽  
Opposite Effect ◽  
Eutectic Temperature ◽  
Alloying Elements ◽  
Qualitative Model ◽  
Eutectic Alloys ◽  
Temperature Growth

ABSTRACTThe effect of small additions of Si, P, Cr, Mn and Ti on transition velocities from grey to white and white to grey of pure Fe-C eutectics has been measured by varying growth rates in directional solidification experiments. Growth undercoolings were measured as a function of growth rate, while white and grey eutectic temperatures were obtained from DTA experiments. As a result of these experiments, alloying elements can be classified into three categories : graphitizing (Si, P), carburizing (Cr) and “opposite effect” (Mn, Ti). Each category is characterized by a given influence on eutectic temperature, growth undercooling, and nucleation of cementite. A qualitative model which permits determination of the influence of alloying elements on these latter three parameters is proposed.

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