On describing microbial growth kinetics from continuous culture data: Some general considerations, observations, and concepts

Law, A. T.; Robertson, Betsy R.; Dunker, S. S.; Button, D. K.

doi:10.1007/bf02011647

Cited by 31 publications

(14 citation statements)

References 24 publications

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“…Thus, while the measurements are taken as a best available reflection of absolute rates, r 2 values overstate precision, and values here are insufficient to address the precise shape of kinetic curves. A similar large disparity was previously noted for phosphate kinetics and was minimized by reducing culture disturbance during sampling (26). This topic will be further addressed in combination with freshwater kinetics.…”

Section: Methodsmentioning

confidence: 52%

Experimental and Theoretical Bases of Specific Affinity, a Cytoarchitecture-Based Formulation of Nutrient Collection Proposed To Supercede the Michaelis-Menten Paradigm of Microbial Kinetics

Button

Robertson

Gustafson

et al. 2004

Appl Environ Microbiol

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A theory for solute uptake by whole cells was derived with a focus on the ability of oligobacteria to sequester nutrients. It provided a general relationship that was used to obtain the kinetic constants for in situ marine populations in the presence of naturally occurring substrates. In situ affinities of 0.9 to 400 liters g of cells ؊1h ؊1 found were up to 10 3 times smaller than those from a "Marinobacter arcticus " isolate, but springtime values were greatly increased by warming. Affinities of the isolate for usual polar substrates but not for hydrocarbons were diminished by ionophores. A kinetic curve or Monod plot was constructed from the best available data for cytoarchitectural components of the isolate by using the theory together with concepts and calculations from first principles. The order of effect of these components on specific affinity was membrane potential > cytoplasmic enzyme concentration > cytoplasmic enzyme affinity > permease concentration > area of the permease site > translation coefficient > porin concentration. Component balance was influential as well; a small increase in cytoplasmic enzyme concentration gave a large increase in the effect of permease concentration. The effect of permease concentration on specific affinity was large, while the effect on K m was small. These results are in contrast to the Michaelis-Menten theory as applied by Monod that has uptake kinetics dependent on the quality of the permease molecules, with K m as an independent measure of affinity. Calculations demonstrated that most oligobacteria in the environment must use multiple substrates simultaneously to attain sufficient energy and material for growth, a requirement consistent with communities largely comprising few species.The rate of nutrient transport into microorganisms is typically described by using the equations of Monod (30), formulations that are based on measurements of in vitro enzyme solutions and the theory described by Michaelis and Menten (29). Affinity for solute is usually taken as the Michaelis constant (K m ), the concentration of substrate at half the maximal rate of uptake, and taken as an inherent property of both the population (42) and its permeases (36). However, the variation of 10 10 in K m values was too great to be attributed to differences in proteins of common function and appears simply to reflect the concentration of proteins involved in substrate acquisition, metabolism, and biosynthesis. This concept was reinforced by equations that reflected the uptake rates from the number of permease molecules, the time required for each permease to translocate a molecule of substrate (6), and internal pool concentrations generated at the resulting dynamic steady-state equilibrium (5). Specific affinity for substrate S (a S ), a second-order rate constant for substrate sequestering that scales with nutrient acquisition power independently of the maximal rate (37), could thus be related to cytoarchitectural composition, including permease abundance and properties. The purpose of thi...

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Section: Methodsmentioning

confidence: 52%

Experimental and Theoretical Bases of Specific Affinity, a Cytoarchitecture-Based Formulation of Nutrient Collection Proposed To Supercede the Michaelis-Menten Paradigm of Microbial Kinetics

Button

Robertson

Gustafson

et al. 2004

Appl Environ Microbiol

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“…Further data are needed to show if the familiar model developed by Monod is also valid for growth on substrate mixtures or if the kinetics of mixed-substrate growth must be solved in another way (e.g. see Law et al, 1976).…”

Section: Discussionmentioning

confidence: 99%

Regulation of Enzyme Synthesis and Variation of Residual Methanol Concentration during Carbon-limited Growth of Kloeckera sp. 2201 on Mixtures of Methanol and Glucose

Egli¹,

Lindley²,

Quayle³

1983

Microbiology

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The methylotrophic yeast Kloeckera sp. 2201 was grown in double carbon (glucose/methanol) limitation in a chemostat at a constant dilution rate and the regulation of the synthesis of enzymes involved in the assimilation of methanol and the breakdown of glucose was studied as a function of the composition of the glucose/methanol mixture in the inflowing medium. Enhanced synthesis of most of the enzymes taking part in the assimilation of C, units took place despite the presence of glucose in the medium. Depending on the enzyme, 40 to 60% (w/w of total substrate) methanol in the mixture was enough to cause maximal induction and no further enhancement of their specific activities was observed during growth on mixtures containing higher methanol/glucose ratios. The only two enzymes involved in the assimilation of methanol not showing these characteristic patterns were 'classical' transketolase and transaldolase. Substrate fluxes through the individual steps of glucose and methanol metabolism have been calculated and compared with the experimentally determined specific activities of the enzymes concerned. The three enzymes whose specific activities were least in excess of the substrate flux calculated to be catalysed by them were transketolase, transaldolase and (possibly) di hydroxyacetone synthase.The residual concentration of methanol was measured in the culture as a function of the composition of the supplied glucose/methanol mixture. During growth with mixtures the concentration of methanol was always lower than during growth with this substrate as the only carbon source. Possible ecological advantages accruing to a facultative methylotroph as a consequence of this behaviour are discussed.

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“…The biofilm density X and biofilm thickness L were f f estimated from biomass measurements conducted after each biokinetic experiment using appropriate empirical correla-Ž . tions Law et al, 1976;Pirbazari et al, 1993 Adsorption Equilibrium Parameters. The mini-column adsorption experiments facilitated the generation of a series of TCE breakthrough profiles corresponding to different influent concentrations and GAC masses.…”

Section: Determination Of Model Parametersmentioning

confidence: 99%

Modeling and design of vapor‐phase biofiltration for chlorinated volatile organic compounds

Den

Pirbazari

2002

AIChE Journal

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IntroductionIndustrial gas-phase emissions of hazardous contaminants Ž . including volatile organic compounds VOCs are widely regarded as risks to environmental and occupational health. A broad spectrum of innovative treatment technologies are currently available for the control of such industrial emissions, among which biofiltration is a viable alternative. The biofiltration process involves the growth of heterotrophic microorganisms immobilized on a solid surface and sustained by the organic components of the gas stream. The technology has several advantages over traditional physical or chemical processes such as thermal destruction, carbon adsorption, and liquid scrubbing; and these include low energy consumption, and, consequently, low operating and maintenance costs. Ž . Furthermore, granular activated carbon GAC employed as a biofilter packing material not only provides a favorable environment for biofilm growth, but also extends the contact time between the biofilm and contaminants due to its desirCorrespondence concerning this article should be addressed to M. Pirbazari. Current address of W. Den: Dept. of Environmental Science, Tunghai University, Tai-Chung, Taiwan. able adsorptive characteristics. These beneficial features attributed to the adsorptive characteristics of GAC and biodegradative ability of the biofilm are particularly important in the degradation of recalcitrant compounds. These aspects have been well addressed by several researchers in both Ž aqueous-phase systems Ying and Weber, 1979; Kim and Pir-. bazari, 1989; Ravindran et al., 1997 and in gas-phase systems Ž . De heyder et al., 1994; Man et al., 1996 . An important aspect regarding implementation of full-scale biofiltration systems is their economic planning and design. A modeling and design protocol may indeed be a valuable tool to minimize the scope of elaborate, time-consuming, and expensive pilot-scale testing normally considered before a fullscale design is contemplated upon. Therefore, the present study focuses on the development of a mathematical modeling technique for performance prediction and simulation of biofilters under various operating conditions. The proposed model has the versatility of using either adsorbing or nonadsorbing media. The study is also intended to establish a systematic approach in determining the model input parameters, and to verify the predictive capability of the model. In the present study, GAC was employed as the biofilter packSeptember 2002 Vol. 48, No. 9AIChE Journal 2084 Ž . ing medium, and trichloroethylene TCE was chosen as the model compound.

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On describing microbial growth kinetics from continuous culture data: Some general considerations, observations, and concepts

Cited by 31 publications

References 24 publications

Experimental and Theoretical Bases of Specific Affinity, a Cytoarchitecture-Based Formulation of Nutrient Collection Proposed To Supercede the Michaelis-Menten Paradigm of Microbial Kinetics

Experimental and Theoretical Bases of Specific Affinity, a Cytoarchitecture-Based Formulation of Nutrient Collection Proposed To Supercede the Michaelis-Menten Paradigm of Microbial Kinetics

Regulation of Enzyme Synthesis and Variation of Residual Methanol Concentration during Carbon-limited Growth of Kloeckera sp. 2201 on Mixtures of Methanol and Glucose

Modeling and design of vapor‐phase biofiltration for chlorinated volatile organic compounds

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