Skip to main content

Growth Kinetics of Cell Cultures

  • Chapter
  • First Online:
Bioreaction Engineering Principles

Abstract

In Chaps. 3 and 5, we have discussed how the two important design parameters for cell cultures, yield and productivity, can be derived from experimental data, e.g., from measurements of the substrate consumption and the product formation. Furthermore, we have shown how measured steady-state fluxes in and out of the cell, the exchange fluxes, can be used to calculate the fluxes through the different branches of the metabolic network of a given microorganism.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 84.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 109.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 109.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Notes

  1. 1.

    An operon contains a cluster of genes that are all under the control of a single regulatory signal or promoter. They are transcribed together onto a single RNA strand and can be translated together. They also found both in prokaryotes and eukaryotes.

  2. 2.

    The true inducer is allolactose, and some small lactose flux – perhaps by passive diffusion into the cell, is permitted.

  3. 3.

    Since the total number of operators of a given type in the cell is very small, it does not make much sense to talk about the fraction of repressor-free operators. However, in a description of enzyme synthesis, one may use (7.47) as an expression for the probability that the operator is repressor free.

  4. 4.

    Conidiphores are modified hyphae on which the asexual spores are formed.

  5. 5.

    The assumption of an infinitely fast reaction is a bit shaky. It means that C has to diffuse at a constant rate up to the boundary z = 0, react instantly with S, and move away toward z = d at the same rate. This is unrealistic as shown by Schultz et al. (1974), unless the following relation is true: Q = kd 2/D >> 1. For a rate constant k = 107 s−1, d = 10 nm, and D = 10−12 m2 s−1, Q = 10 which can be shown to give an overestimation of the flux by about 10%. An error of this magnitude does, however, not invalidate the results obtained above.

  6. 6.

    Benzoic acid as well as citric acid and lactic acid are used to preserve food, exactly because of their inhibition of microbial growth. In acidified food (it could be a soft drink or a fruit juice, or the pH may start to decrease through incipient growth of spoilage bacteria) much of the benzoic acid is on the undissociated form (pK a = 4.1), and the undissociated acid freely diffuses into the cell. In anaerobic yeast cultivation, growth of the yeast almost stops when pH reaches 5, but the ethanol yield increases in a frantic effort of the yeast cell to acquire enough ATP to expulse the protons after the acid has dissociated at the intracellular pH of close to 7. Lactic acid (pK a = 3.88) has the same effect.

References

  • Agger, T., Spohr, A. B., Carlsen, M., Nielsen, J. (1998). Growth and product formation of Aspergillus oryzae during submerged cultivations: Verification of a morphologically structured model using fluorescent probes. Biotechnol. Bioeng. 57, 321–329.

    Article  CAS  Google Scholar 

  • Baltzis, B. C., Fredrickson, A. G. (1988). Limitation of growth by two complementary nutrients: Some elementary, but neglected considerations. Biotechnol. Bioeng. 31, 75–86.

    Article  CAS  Google Scholar 

  • Benthin, S., Nielsen, J., Villadsen, J. (1991). A simple and reliable method for the determination of cellular RNA content. Biotechnol. Techniques 5, 39-42.

    Article  CAS  Google Scholar 

  • Benthin, S., Nielsen, J., Villadsen, J. (1993a). Two uptake systems for fructose in Lactococcus lactis subsp. cremoris FD1 produce glycolytic and gluconogenic fructose phosphates and induce oscillations in the growth and lactic acid formation. Appl. Environ. Microbiology, 59, 3206–3211.

    CAS  Google Scholar 

  • Benthin, S., Nielsen, J., Villadsen, J. (1993b). Transport of sugars via two anomer-specific sites on mannose.phophotransferase system in Lactococcus cremoris: In vivo study of mechanism, kinetics, and adaptation. Biotechnol. Bioeng. 42, 440–448.

    Article  CAS  Google Scholar 

  • Benthin, S., Nielsen, J., Villadsen, J. (1994). Galactose expulsion during lactose metabolism in Lactococcus lactis due to dephosphorylation of intracellular galactose 6-phosphate. Appl. Envir. Microbiol. 60, 1254–1259.

    CAS  Google Scholar 

  • Beuse, M., Kopmann, A., Diekmann, H., Thoma, M. (1999). Oxygen, pH value and carbon source induced changes in the mode of oscillation in synchronous continuous culture of Saccharomyces cerevisiae. Biotechnol. Bioeng. 63, 410–417.

    Article  CAS  Google Scholar 

  • Bibal, B., Goma, G., Vayssier, Y., Pareilleux, A. (1988). Influence of pH, lactose and lactic acid on the growth of Streptococcus cremoris: A kinetic study. Appl. Microbiol. Biotechnol. 28, 340–344.

    Article  CAS  Google Scholar 

  • Bibal, B., Kapp, C., Goma, G., Pareilleux, A. (1989). Continuous culture of Streptococcus cremoris on lactose using various medium conditions. Appl. Microbiol. Biotechnol. 32, 155–159.

    Article  CAS  Google Scholar 

  • Caldwell, I. Y., Trinci, A. P. J. (1973). The growth unit of the mould Geotrichum candidum. Arch. Microbiol. 88, 1–10.

    CAS  Google Scholar 

  • Carlsen, M., Jocumsen, K. V., Emborg, C., Nielsen, J. (1997) Modelling the growth and Proteinase A production in continuous cultures of recombinant Saccharomyces cerevisiae. Biotechnol. Bioeng. 55, 447–454

    Article  CAS  Google Scholar 

  • Christiansen, T., Spohr, A., Nielsen, J. (1999) On-line study of growth kinetics of single hyphae of Aspergillus oryzae in a flow-through cell. Biotechnol. Bioeng. 63, 147–153

    Article  CAS  Google Scholar 

  • Cox, P. W., Paul, G. C., Thomas, C. R. (1998) Image analysis of the morphology of filamentous micro-organisms. Microbiol. 144, 817–827.

    Article  CAS  Google Scholar 

  • Domach, M. M., Leung, S. K., Cahn, R. E., Cocks, G. G., Shuler, M. L. (1984). Computer model for glucose-limited growth of a single cell of Escherichia coli B/r-A, Biotechnol. Bioeng. 26, 203–216.

    Article  CAS  Google Scholar 

  • Duboc, P., von Stockar, U., and Villadsen, J.(1998). Simple generic model for dynamic experiments with Saccharomyces cerevisiae in continuous culture. Biotechnol. Bioeng. 60, 180–189.

    Article  CAS  Google Scholar 

  • Duboc, P., von Stockar, U. (2000). Modeling of oscillating cultivations of Saccharomyces cerevisiae: Identification of population structure and expansion kinetics based on on-line measurements. Chem. Eng. Sci. 55, 149–160.

    Article  CAS  Google Scholar 

  • Egli, T. (1991). On multiple nutrient limited growth of microorganisms with special reference to dual limitation by carbon and nitrogen substrates. Antonie van Leeuwenhoek 60, 2257–234.

    Article  CAS  Google Scholar 

  • Esener, A. A., Roels, J. A., Kossen, N. W. F. (1981a). The influence of temperature on the maximum specific growth rate of Klebsiella pneumoniae. Biotechnol. Bioeng. 23, 1401–1405.

    Article  Google Scholar 

  • Esener, A. A., Roels, J. A., Kossen, N. W. F. (1981b). Fed-batch culture: Modeling and applications in the study of microbial energies. Biotechnol. Bioeng. 27, 1851–1871.

    Article  Google Scholar 

  • Esener, A. A., Roels, J. A., Kossen, N. W. F., Roozenburg, J. W. H. (1981c). Description of microbial growth behaviour during the wash-out phase; determination of the maximum specific growth rate. Eur. J. Appl. Microbiol. Biotechnol. 13, 141–144.

    Article  Google Scholar 

  • Esener, A. A., Veerman, T., Roels, J. A., Kossen, N. W. F. (1982). Modeling of bacterial growth; Formulation and evaluation of a structured model. Biotechnol. Bioeng. 29, 1749–1764.

    Article  Google Scholar 

  • Fiddy, C. and Trinci, A. P. J. (1976). Mitosis, septation, branching and the duplication cycle in Aspergillus nidulans. J. Gen. Microbiol. 97, 169–184.

    CAS  Google Scholar 

  • Frandsen, S. (1993). Dynamics of Saccharomyces cerevisiae in Continuous culture, Ph.D. thesis, Technical University of Denmark, Lyngby.

    Google Scholar 

  • Fredrickson, A. G. (1976). Formulation of structured growth models. Biotechnol. Bioeng. 18, 1481–1486.

    Article  CAS  Google Scholar 

  • Harder, A., Roels, J. A. (1982). Application of simple structured models in bioengineering. Adv. Biochem. Eng. 21, 55–107.

    CAS  Google Scholar 

  • Henriksen, C. M., Nielsen, J., Villadsen, J. (1998). Modelling of the protonophoric uncoupling by phenoxyacetic acid of the plasma membrane of Penicillium chrysogenum. Biotechnol. Bioeng. 60, 761–767.

    Article  CAS  Google Scholar 

  • Herbert, D. (1959). Some principles of continuous culture. Recent Prog. Microbiol. 7, 381–396.

    Google Scholar 

  • Herendeen, S. L., van Bogelen, R. A., Neidhardt, F. C. (1979). Levels of major proteins of Escherichia coli during growth at different temperatures. J. Bacteriol. 139, 185–194.

    CAS  Google Scholar 

  • Hjortso, M. A. and Nielsen, J. (1994). A conceptual model of autonomous oscillations in microbial cultures. Chem. Eng. Sci. 49, 1083–1095.

    Article  CAS  Google Scholar 

  • Ingraham, J. L., Maalöe, O., Neidhardt, F. C. (1983). Growth of the Bacterial Cell, Sinauer Associates, Inc., Sunderland.

    Google Scholar 

  • Jacob, F., Monod, J. (1961). Genetic regulatory processes in the synthesis of proteins. J. Mol. Biol. 3, 318–356.

    Article  CAS  Google Scholar 

  • Jöbses, I. M. L., Egberts, G. T. C., van Baalen, A., Roels, J. A. (1985). Mathematical modeling of growth and substrate conversion of Zymomonas mobilis at 30 and 35°C, Biotechnol. Bioeng. 27, 984–995.

    Article  Google Scholar 

  • Keulers, M., Satroutdinov, A. D., Suszuki, T., Kuriyama, H. (1996a). Synchronization affector of autonomous short period sustained oscillation of Saccharomyces cerevisiae. Yeast 12, 673682.

    Google Scholar 

  • Keulers, M., Suzuki, T., Satroutdinov, A. D., Kuriyama, H. (1996b). Autonomous metabolic oscillation in continuous culture of Saccharomyces cerevisiae grown on ethanol. FEMS Microbiol. Letters 142, 253258.

    Article  CAS  Google Scholar 

  • Kompala, D. S., Ramkrishna, D., Tsao, G. T. (1984). Cybernetic modeling of microbial growth on multiple substrates. Biotechnol. Bioeng. 26, 1272–1281.

    Article  CAS  Google Scholar 

  • Kompala, D. S., Ramkrishna, D., Jansen, N. B., Tsao, G. T. (1986). Investigation of bacterial growth on mixed substrates: Experimental evaluation of cybernetic models. Biotechnol. Bioeng. 28, 1044–1055.

    Article  CAS  Google Scholar 

  • Krabben, P., Nielsen, J. (1998) Modeling the mycelium morphology of Penicillium species in submerged cultures. Adv. Biochem. Eng./Biotechnol. 60, 125–152.

    Google Scholar 

  • Lee, S. B., Bailey, J. E. (1984a). A mathematical model for λdv plasmid replication: Analysis of wild-type plasmid, Plasmid 11, 151–165.

    Article  CAS  Google Scholar 

  • Lee, S. B., Bailey, J. E. (1984b). A mathematical model for λdv plasmid replication: Analysis of copy number mutants. Plasmid 11, 166–177.

    Article  CAS  Google Scholar 

  • Lee, S. B., Bailey, J. E. (1984c). Analysis of growth rate effects on productivity of recombinant Escherichia coli populations using molecular mechanism models. Biotechnol. Bioeng. 26, 66–73.

    Article  CAS  Google Scholar 

  • Lee, S. B., Bailey, J. E. (1984d). Genetically structured models for lac promoter-operator function in the Escherichia coli chromosome and in multicopy plasmids: lac operator function. Biotechnol. Bioeng. 26, 1372–1382.

    Article  CAS  Google Scholar 

  • Lee, S. B., Bailey, J. E. (1984e). Genetically structured models for lac promoter-operator function in the Escherichia coli chromosome and in multicopy plasmids: lac promoter function. Biotechnol. Bioeng. 26, 1381–1389.

    Google Scholar 

  • Lengeler, J. W., Drews, G., Schegel, H. G. (1999). Biology of the Prokaryotes. Thieme Verlag, Stuttgart.

    Google Scholar 

  • McIntyre, M., Müller, C., Dynesen, J., Nielsen, J. (2001). Metabolic engineering of the morphology of Aspergillus. Adv. Biochem. Eng./Biotechnol. 73, 103–128.

    Google Scholar 

  • Megee, R. D., Kinishita, S., Fredrickson, A. G., Tsuchiya, H. M. (1970). Differentiation and product formation in molds. Biotechnol. Bioeng. 12, 771–801.

    Article  CAS  Google Scholar 

  • Melchiorsen, C. R., Jensen, N. B. S., Christensen, B., Jochumsen, K. V., Villadsen, J. (2001). Dynamics of pyruvate metabolism in Lactococcus lactis. Biotechnol. Bioeng. 74, 271–279.

    Article  CAS  Google Scholar 

  • Monod, J. (1942). Recherches sur la croissance des cultures bacteriennes, Hermann et Cie, Paris.

    Google Scholar 

  • Monod, J. (1965). From enzymatic adaption to allosteric transitions. Nobel lecture December 11, 1965 (in “Nobel lectures, Physiology and Medicine 1963-1970”, Elsevier, 1972).

    Google Scholar 

  • Monod, J., Wyman, J., Changeux, J.-P. (1963). Allosteric proteins and cellular control systems. J. Mol. Biol. 6, 306–329.

    Article  CAS  Google Scholar 

  • Nielsen, J. (1992). Modelling the growth of filamentous fungi. Adv. Biochem. Eng. Biotechnol. 46, 187–223.

    CAS  Google Scholar 

  • Nielsen, J. (1993). A simple morphologically structured model describing the growth of filamentous microorganisms. Biotechnol. Bioeng. 41, 715–727.

    Article  CAS  Google Scholar 

  • Nielsen, J. (1996). Modelling the morphology of filamentous microorganisms. TIBTECH 14, 438–443.

    Article  CAS  Google Scholar 

  • Nielsen, J. (1997). Physiological engineering aspects of Penicillium chrysogenum. World Scientific Publishing Co., Singapore.

    Google Scholar 

  • Nielsen, J., Villadsen, J. (1992). Modeling of microbial kinetics, Chem. Eng. Sci. 47, 4225–4270.

    Article  CAS  Google Scholar 

  • Nielsen, J., Villadsen, J. (1994). Bioreaction Engineering Principles. 1st edition, Plenum Press, New York.

    Google Scholar 

  • Nielsen, J., Nikolajsen, K., Villadsen, J. (1991a). Structured modeling of a microbial system 1. A theoretical study of the lactic acid fermentation. Biotechnol. Bioeng. 38, 1–10.

    Article  CAS  Google Scholar 

  • Nielsen, J., Nikolajsen, K., Villadsen, J. (1991b). Structured modeling of a microbial system 2. Verification of a structured lactic acid fermentation model. Biotechnol. Bioeng. 38, 11–23.

    Article  CAS  Google Scholar 

  • Nielsen, J., Pedersen, A. G., Strudsholm, K., Villadsen, J. (1991c). Modeling fermentations with recombinant microorganisms: Formulation of a structured model. Biotechnol. Bioeng. 37, 802–808.

    Article  CAS  Google Scholar 

  • Patnaik, P. R. (2003). Oscillatory metabolism of Saccharomyces cerevisiae: An overview of mechanisms and models. Biotechnology Advances, 21, 183192.

    Article  CAS  Google Scholar 

  • Peretti, S. W., Bailey, J. E. (1986). Mechanistically detailed model of cellular metabolism for glucose-limited growth of Escherichia coli B/r-A. Biotechnol. Bioeng. 28, 1672–1689.

    Article  CAS  Google Scholar 

  • Peretti, S. W., Bailey, J. E. (1987). Simulations of host–plasmid interactions in Escherichia coli: Copy number, promoter strength, and ribosome binding site strength effects on metabolic activity and plasmid gene expression. Biotechnol. Bioeng. 29, 316–328.

    Article  CAS  Google Scholar 

  • Pirt, S. J. (1965). The maintenance energy of bacteria in growing cultures. Proc. Royal Soc. London Ser. B. 163, 224-231.

    Article  CAS  Google Scholar 

  • Pronk, J. T., Steensma, H. Y., van Dijken, J. P. (1996). Pyruvate metabolism in Saccharomyces cerevisiae. Yeast 12, 16071633.

    Article  CAS  Google Scholar 

  • Prosser, J. I., Tough, A. J. (1991). Growth mechanisms and growth kinetics of filamentous microorganisms, Crit. Rev. Biotechnol. 10, 253–274.

    Article  CAS  Google Scholar 

  • Ramkrishna, D. (1982). A cybernetic perspective of microbial growth, in Foundations of Biochemical Engineering: Kinetics and Thermodynamics in Biological Systems, American Chemical Society, 161–178.

    Google Scholar 

  • Ramkrishna, D., Fredrickson, A. G., Tsuchiya, H. M. (1967). Dynamics of microbial propagation: Models considering inhibitors and variable cell composition. Biotechnol. Bioeng. 9, 129–170.

    Article  Google Scholar 

  • Ramkrishna, D., Kompala, D. S., Tsao, G. T. (1987). Are microbes optimal strategists? Biotechnol. Prog. 3, 121–126.

    Article  Google Scholar 

  • Rieger, M., Käppeli, O., Fiechter, A. (1983). The role of limited respiration in the incomplete oxidation of glucose by Saccharomyces cerevisiae. J. Gen. Microbiol. 129, 653–661.

    CAS  Google Scholar 

  • Robinson, P. M. and Smith, J. M. (1979). Development of cells and hyphae of Geotrichum candidum in chemostat and batch culture. Proc. Br. Mycol. Soc. 72, 39–47.

    Article  Google Scholar 

  • Roels, J. A. (1983). Energetics and Kinetics in Biotechnology. Elsevier Biomedical Press, Amsterdam.

    Google Scholar 

  • Roels, J. A., Kossen, N. W. F. (1978). On the modeling of microbial metabolism, Prog. Ind. Microbiol. 14, 95–204.

    CAS  Google Scholar 

  • Schultz, J. S., Goddard, J. D., Suchdeo, S. R. (1974). Facilitated transport via carrier mediated diffusion in membranes, Part I and II. AIChE J, 20, 417–445 and 625–645.

    Google Scholar 

  • Schulze, U. (1995). Anaerobic physiology of Saccharomyces cerevisiae. Ph.D. Thesis, Technical University of Denmark.

    Google Scholar 

  • Seo, J.-H., Bailey, J. E. (1985). Effects of recombinant plasmid content on growth properties and cloned gene product formation in Escherichia coli. Biotechnol. Bioeng. 27, 1668–1674.

    Article  CAS  Google Scholar 

  • Shuler, M. L., Domach, M. M. (1982). Mathematical models of the growth of individual cells, in Foundations of Biochemical Engineering: Kinetics and Thermodynamics in Biological Systems, American Chemical Society Publications, 93–133.

    Google Scholar 

  • Sohn, H. Y., Kuriyama, H. (2001). Ultradian metabolic oscillation of Saccharomyces cerevisiae during aerobic continuous culture: Hydrogen sulphide, a population synchronizer, is produced by sulphite reductase. Yeast 18, 125–135.

    Article  CAS  Google Scholar 

  • Song, H. S., Ramkrishna, D. (2010). Prediction of metabolic function from limited data: Lumped Hybrid Cybernetic Modeling (L-HCM). Biotechnol. Bioeng. 106, 271–284.

    CAS  Google Scholar 

  • Sonnleitner, B., Käppeli, O. (1986). Growth of Saccharomyces cerevisiae is controlled by its limited respiratory capacity: Formulation and verification of a hypothesis. Biotechnol. Bioeng. 28, 927–937.

    Article  CAS  Google Scholar 

  • Spohr, A. B., Mikkelsen, C. D., Carlsen, M., Nielsen, J., Villadsen, J. (1998) On-line study of fungal morphology during submerged growth in a small flow-through cell. Biotechnol. Bioeng. 58, 541–553.

    Article  CAS  Google Scholar 

  • Stein, W. D. (1990). Channels, Carriers and Pumps. An Introduction to Membrane Transport. Academic Press, San Diego.

    Google Scholar 

  • Strässle, C., Sonnleitner, B., Fiechter, A. (1988). A predictive model for the spontaneous synchronization of Saccharomyces cerevisiae grown in continuous culture I. Concept, J. Biotechnol. 7, 299–318.

    Article  Google Scholar 

  • Strässle, C., Sonnleitner, B., Fiechter, A. (1989). A predictive model for the spontaneous synchronization of Saccharomyces cerevisiae grown in continuous culture II. Experimental verification. J. Biotechnol. 9, 191–208.

    Article  Google Scholar 

  • Strudsholm, K., Nielsen, J., Emborg, C. (1992). Product formation during hatch fermentation with recombinant E. coli containing a runaway plasmid, Bioproc. Eng. 8, 173–181.

    Article  CAS  Google Scholar 

  • Trinci, A. P. J. (1974). A study of the kinetics of hyphal extension and branch initiation of fungal mycelia. J. Gen. Microbiol. 81, 225–236.

    CAS  Google Scholar 

  • Trinci, A. P. J. (1984). Regulation of hyphal branching and hyphal orientation. In The Ecology and Physiology of the Fungal Mycelium, D. H. Jennings and A. D. M. Rayner, eds., Cambridge University Press, Cambridge, UK.

    Google Scholar 

  • Tsao, G. T., Hanson, T. P. (1975). Extended Monod equation for batch cultures with multiple exponential phases. Biotechnol. Bioeng. 17, 1591–1598.

    Article  Google Scholar 

  • Turner, B. G., Ramkrishna, D. (1988). Revised enzyme synthesis rate expression in cybernetic models of bacterial growth. Biotechnol. Bioeng. 31, 41–43.

    Article  CAS  Google Scholar 

  • Verduyn, C., Postma, E., Scheffers, W. A., van Dijken, J. P. (1992). Effect of benzoic acid on metabolic fluxes in yeast. A continuous culture study on the regulation of respiration and alcoholic fermentation. Yeast 8, 501–517.

    Article  CAS  Google Scholar 

  • Williams, F. M. (1967). A model of cell growth dynamics. J. Theoret. Biol. 15, 190–207.

    Article  CAS  Google Scholar 

  • Young, J. D., Henne, K. L., Morgan, A. E., Konopka, A. E., Ramkrishna, D. (2008). Integrating cybernetic modeling with pathway analysis provides a dynamic, systems-level description of metabolic control. Biotechnol. Bioeng. 100, 543–559.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to John Villadsen .

Problems

Problems

Problem 7.1 Estimation of parameters in the Monod model

From measurements of the residual glucose concentration in a steady-state chemostat at various dilution rates, you can find the following results:

D (h−1)

s (mg L−1)

0.13

11

0.19

14

0.23

18

0.36

38

0.67

85

0.73

513

Calculate by linear regression the parameters in the Monod model. Are any of the data points suspect?

If you want to check the value of μ max determined above, increase the dilution rate in the chemostat to D = 1.1 h−1. This results in a rapid increase of the glucose concentration in the medium. After a while, s >> K s. The result of the change in dilution rate is a decrease in the biomass concentration, and during the wash-out you measure the biomass concentration as a function of time, and obtain the following results:

Time (h)

x (g L−1)

0

5.1

0.5

4.5

1.0

3.7

2.0

2.8

3.0

2.1

4.0

1.4

Determine μ max from this experiment. Discuss the applied method [see also Esener et al. (1981c)].

Problem 7.2Inhibitory effect of lactic acid

Bibal et al. (1988, 1989) studied the inhibition of lactic acid on Streptococcus cremoris, and in this exercise we will analyze their data.

  1. (a)

    The influence of lactic acid on the growth of S. cremoris was examined by measuring the maximum specific growth rate during batch growth of the bacterium in media containing various concentrations of lactic acid (p). The results are summarized below:

    p (g L−1)

    μ (h−1)

    0

    0.90

    12.0

    0.68

    39.0

    0.52

    55.0

    0.13

    As discussed in Example 7.11, it is mainly the undissociated form of lactic acid that passes through the cellular membrane, and we will therefore assume that it is only the undissociated acid that has a toxic effect on the cells. Plot the relative specific growth rate, i.e., μ max(p)/μ max(p = 0), versus the concentration of the undissociated acid concentration (in mM). pH = 6.3 was used and pK a for lactic acid is 3.88. Assume that the inhibition model given by (7.19) holds. Find the inhibition constant K i . Plot the model together with the experiments.

  2. (b)

    From the results in (a) you conclude that (7.19) is not well suited for description of the experimental data, since the inhibition by lactic acid seems to be stronger, especially at high values of undissociated lactic acid concentrations (p u). There seems to be a certain maximum concentration of undissociated acid above which growth stops. Next try the model (7.20) to find the influence of p u on μ, and estimate the model parameter. At what concentration of lactic acid will growth stop?

  3. (c)

    Plot the maximum specific growth rate as a function of the pH in a medium containing 1 and 10 g L−1 of lactic acid (total concentration), using the model found in (b).

  4. (d)

    Measuring the yield coefficient on lactose in a steady-state chemostat at different concentrations of lactic acid, Bibal et al. (1988, 1989) found the data below:

    p (g L−1)

    Y sx (g DW g−1)

    0

    0.16

    7.5

    0.16

    13.0

    0.14

    18.5

    0.14

    21.0

    0.14

    32.0

    0.12

    38.5

    0.11

    45.0

    0.10

    48.5

    0.09

    How can you explain the decrease in the yield coefficient with increasing lactic acid concentration?

  5. (e)

    Assume that the maintenance coefficient m s is 0.05 h−1. Calculate the true yield coefficient in (7.27) for p = 0. Using the model derived in (b), calculate the maintenance coefficient as a function of p u. Explain the results.

Problem 7.3Modeling of the lac-operon in E. coli

We will now revisit the model for the lac-operon described in Sect. 7.5.1.

  1. (a)

    The repressor has four binding sites for the inducer (lactose), but in the derivation of (7.47) only the repressor–inducer complex where all four sites are occupied is considered. We now consider binding at all four sites. Specify all the equilibria and the definitions of the association constants. The association constant for formation of X r S i is termed K 1i , and that for formation of X O X r S i is termed K 4i . Binding of the inducer to the repressor operator complex can be neglected (i.e., the equilibrium in (7.39c) is not considered).

    Assume that the affinity for the binding of the repressor to the operator is approximately the same whether no, one, two, or three inducers are bound to the repressor, i.e., K 41 = K 42 = K 43 = K 44. This assumption is reasonable since the repressor probably changes its conformation only when the last inducer is bound to it. With this assumption show that the fraction of repressor-free operators is given by

    $$\hskip 16pt{Q_1} = \frac{{\left[ {{X_{\rm{O}}}} \right]}}{{{{\left[ {{X_{\rm{O}}}} \right]}_{\rm{t}}}}} = \frac{{1 + {K_1}\left[ {{S_{\rm{lac}}}} \right]_{\rm{t}}^4}}{{1 + {K_1}\left[ {{S_{\rm{lac}}}} \right]_{\rm{t}}^4 + {K_2}{{\left[ {{X_{\rm{r}}}} \right]}_{\rm{t}}} + {K_{\rm{S}}}{K_{11}}\left[ {{X_{\rm{r}}}{S_{\rm{lac}}}} \right]{{\left[ {{S_{\rm{lac}}}} \right]}_{\rm{t}}}\left( {1 + {K_{12}}{{\left[ {{S_{\rm{lac}}}} \right]}_{\rm{t}}} + {K_{12}}{K_{13}}\left[ {{S_{\rm{lac}}}} \right]_{\rm{t}}^2} \right)}}. $$
    (1)

    In (1), K 1 = K 41 K 42 K 43 K 44.

    We now assume that the K 11K 12K 13K 14, i.e., the association constant for the fourth inducer is much stronger than the corresponding constants for the first three sites. This assumption follows from our assumption above that the conformation of the repressor changes only when the fourth inducer is bound and when the conformation changes the repressor–inducer complex becomes very stable. What other assumptions are required for reducing (1) to (7.47)?

  2. (b)

    Lee and Bailey (1984d) also modeled the lac-operon, but they included binding of the repressor to a nonspecific binding site in the chromosome (X d). Again we neglect binding of inducer to the repressor–operator complex, and the equilibria are therefore

    $$ {X_{\rm{r}}} + n{S_{\rm{lac}}}\;\mathop { \leftrightarrow }\limits^{{K_1}} \;{X_{\rm{r}}}n{S_{\rm{lac}}}, $$
    (2a)
    $$ {X_{\rm{o}}} + {X_{\rm{r}}}\mathop {{\; \leftrightarrow }}\limits^{{K_2}} \;{X_{\rm{o}}}{X_{\rm{r}}}, $$
    (2b)
    $$ {X_{\rm{o}}} + {X_{\rm{r}}}{S_{\rm{lac}}}\;\mathop {{ \leftrightarrow \;}}\limits^{{K_4}} {X_{\rm{o}}}{X_{\rm{r}}}{S_{\rm{lac}}}, $$
    (2c)
    $$ {X_{\rm{d}}} + {X_{\rm{r}}}\;\mathop {{ \leftrightarrow \;}}\limits^{{K_5}} {X_{\rm{d}}}{X_{\rm{r}}}, $$
    (2d)
    $$ {X_{\rm{d}}} + {X_{\rm{r}}}{S_{\rm{lac}}}\;\mathop { \leftrightarrow }\limits^{{K_6}} \;{X_{\rm{d}}}{X_{\rm{r}}}{S_{\rm{lac}}}. $$
    (2e)

    By assuming that [X d]t ≈ [X d], show that

    $$ {Q_1} = \frac{{\left[ {{X_{\rm{O}}}} \right]}}{{{{\left[ {{X_{\rm{O}}}} \right]}_{\rm{t}}}}} = \frac{{1 + {K_5}{{\left[ {{X_{\rm{d}}}} \right]}_{\rm{t}}} + {K_1}\left[ {{S_{\rm{lac}}}} \right]_{\rm{t}}^n\left( {1 + {K_6}{{\left[ {{X_{\rm{d}}}} \right]}_{\rm{t}}}} \right)}}{{1 + {K_5}{{\left[ {{X_{\rm{d}}}} \right]}_{\rm{t}}} + {K_1}\left[ {{S_{\rm{lac}}}} \right]_{\rm{t}}^n\left( {1 + {K_6}{{\left[ {{X_{\rm{d}}}} \right]}_{\rm{t}}}} \right) + {K_2}{{\left[ {{X_{\rm{r}}}} \right]}_{\rm{t}}}}}, $$
    (3)
  3. (c)

    Lee and Bailey (1984d) specified the parameters in (3) to be

    $$ \eqalign{ {K_1} = {1}{0^7}\;{{\hbox{M}}^{ - {1 }}},\quad {K_2} = {2}\; \times \;{1}{0^{{12}}}\;{{\hbox{M}}^{ - {1}}}{,}\quad {K_4} = {2}\; \times \;{1}{0^9}\;{{\hbox{M}}^{ - {1}}} \hfill \\{K_5} = {1}{0^3}\;{{\hbox{M}}^{ - {1}}},\quad {K_6} = {1}.{5}\; \times \;{1}{0^9}\;{{\hbox{M}}^{ - {1}}}. \hfill \\}<!endgathered> $$

    Furthermore, they state that

    $$ {\left[ {{X_{\rm{d}}}} \right]_{\rm{t }}} = { 4}\; \times \;{1}{0^{ - {2}}}\;{\hbox{M}}\ {\hbox{and}}\ { }{\left[ {{X_{\rm{r}}}} \right]_{\rm{t }}} = { 2}\; \times \;{1}{0^{ - {8}}}\;{\hbox{M}}{.} $$

    Plot the value of Q 1 using both (3) and (7.47) as a function of the inducer concentration [S lac]t. Comment on the result.

    The parameters given by Lee and Bailey are for IPTG (isopropyl-β-d-thiogalactosidase), a frequently used inducer in studies of the lac-operon. Assume that the parameters are the same for lactose as inducer and calculate the concentration of lactose (in mg L−1) to give Q 1 = 0.5. Discuss why even this low concentration of lactose leads to induction of the lac-operon.

  4. (d)

    Show that for an antiinducer (neglect binding of the repressor to nonspecific sites)

    $$ {Q_1} = \frac{{\left[ {{X_{\rm{O}}}} \right]}}{{{{\left[ {{X_{\rm{O}}}} \right]}_{\rm{t}}}}} = \frac{{1 + {K_1}\left[ {{S_{\rm{lac}}}} \right]_{\rm{t}}^{\rm{m}}}}{{1 + {K_1}\left[ S \right]_{\rm{t}}^{\rm{n}} + {K_1}{K_4}\left[ S \right]_{\rm{t}}^{\rm{n}}{{\left[ {{X_{\rm{r}}}} \right]}_{\rm{t}}}}}. $$
    (4)

Problem 7.4Facilitated transport through membranes

  1. (a)

    In Example 7.10, (2) [s a >> s b] and negligible contribution from the non-carrier- associated transport, the total volumetric flux v through the membrane area A is

    $$ JA{ } = \frac{{DA}}{d}\frac{{{c_{\rm{t}}}{s_{\rm{a}}}}}{{{K_{\rm{m}}} + {s_{\rm{a}}}}} = \frac{{{v_{\max }}{s_{\rm{a}}}}}{{{K_{\rm{m}}} + {s_{\rm{a}}}}}{\hbox{where}}\,\,{K_{\rm{m}}} = \frac{{{{K\prime}_{\rm{eq}}}}}{K}{\hbox{and}}\,{v_{\max }} = \frac{{DA{c_{\rm{t}}}}}{d}. $$
    (1)

    For uptake of glucose in human erythrocytes (red blood cells), the following data are found experimentally:

    Glucose concentration (mmol L−1)

    Glucose flux (mmol min−1)

    1.0

    0.09

    1.5

    0.12

    2.0

    0.14

    3.0

    0.20

    4.3

    0.25

    5.0

    0.28

    Make a double reciprocal plot of (JA)−1 = v −1 versus s a and determine the parameters v max and K m.

  2. (b)

    In the example, an infinitely fast equilibrium for the reversible reaction \( S{ } + { }C\overset{{{r_{\rm{m}}}}}{\longleftrightarrow} SC \) is postulated.

    Consider the other extreme: an infinitely fast diffusion of C and SC across the membrane, and a slow reaction.

    Now c and sc are both constant and have the values \( \bar{c} \) and \( \bar{s}\bar{c} \) while the solute concentration must vary across the membrane according to

    $$ D\frac{{{{\text{d}}^2}s}}{{{\hbox{d}}{z^2}}} - {k_1}s\bar{c} - {k_2}\bar{s}\bar{c} = 0. $$
    (2)

    with boundary conditions given by (5) of the example.

    Solve the differential equation (2), and determine the values of the two constant carrier concentrations in terms of c t, the two rate constants, and \( \bar{s} = K\displaystyle\frac{{{s_{\rm{a}}} + {s_{\rm{b}}}}}{2}. \)

    [You may consult Note 6.2 since the mathematics involved in this problem is essentially the same as that used in the note, except that plane-parallel symmetry is used here and spherical symmetry in the note]

Problem 7.5Phosphotransferase-based membrane transport systems

Many interesting physiological phenomena can be observed due to the complexity of sugar transport systems.

  1. (a)

    In Benthin et al. (1993a), stable oscillations are observed in both μ and r p because fructose can be taken up by two PTS systems.

    Describe the oscillatory phenomenon, and discuss the mechanism proposed by the authors to explain the complex behavior of the cultivation.

  2. (b)

    In Benthin et al. (1993b), the uptake of glucose and mannose through two specific sites on the transmembrane Mannose-PTS transporter is discussed. It turns out that the transporter is able to distinguish between α glucose and β glucose, an astonishing specificity of the protein.

What is the difference between α and β glucose?

Describe the set of experiments used by the authors to arrive at the conclusion that there must be two different and specific sites on the medium side for uptake of nearly identical sugars.

Discuss the mathematical model used to explain the widely different uptake profiles for α and β glucose after a pulse addition of a mixture of two different sugars.

Finally, discuss the adaptation of the transport system for a chemostat cultivation with constant dilution rate when the medium is changed from mannose limitation to glucose limitation.

Rights and permissions

Reprints and permissions

Copyright information

© 2011 Springer Science+Business Media, LLC

About this chapter

Cite this chapter

Villadsen, J., Nielsen, J., Lidén, G. (2011). Growth Kinetics of Cell Cultures. In: Bioreaction Engineering Principles. Springer, Boston, MA. https://doi.org/10.1007/978-1-4419-9688-6_7

Download citation

Publish with us

Policies and ethics