Lecture 10

April 30, 2008

Nutrient uptake kinetics
and growth rate limitation

1. Nutrient transport kinetics

description

saturable

affinity - binding

general form - saturable hyperbola

equation

2. Michaelis-Menten equation

derivation

assumptions violated

internal pool

back reaction

3. physiological/ecological meaning of parameters

Ks

Vmax

set uptake velocity at a nutrient

comparison of curves

spreadsheet

 

Bifurcation --- PathA - PathB

A4. Nutrient uptake rate, growth rate and cell quota

rho = mu * Q

rho = nutrient uptake rate per cell

Q = cell quota of that element per cell

• minimum
• machinery growth
• storage/intermediates

mu = time^-1 specific growth rate

 

A5. continuous culture fundamentals

fixed volume with dilution

• input of nutrients
• more cells --> less nutrients
• mu = f(nutrient concentration, Q)
• figure

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Path B

B4. uptake rate controls growth

close enough to MM equation

calculate mu from [nutrient]

compare

 

B5. calculate nutrient from growth rate

competition

spreadsheet

species wins that can grow at that rate at the lowest conce

zero net growth (loss = growth)