PART 2 - Kinetics of Substrate Utilization, Product Formation and Biomass Production in Cell Cultures

Question 1

It provides essential insights into the dynamic processes of cell division and proliferation at the molecular level

Answer 1

Cell growth kinetics

Question 2

Jacques Monod described a cell growth model like the _________________________, which describes __________________.

Answer 2

Michaelis–Menten equation
enzymatic reaction

Question 3

This is considered an ideal equation, i.e., an unstructured, unsegregated model called

Answer 3

Monod Growth Kinetics Model.

Question 4

Who did much to elucidate how genes regulate cell metabolism by directing the biosynthesis of enzymes

Answer 4

Jacques Lucien Monod, French biochemist who, with François Jacob,

Question 5

What did Jacques Lucien Monod, French biochemist, with François Jacob win?

Answer 5

They won Nobel Prize for Physiology or Medicine in 1965

Question 6

By carefully manipulating the conditions in the lab, Monod observed how the ___________________
affected the rate at which these microorganisms grew.

Answer 6

availability of nutrients

Question 7

However, this growth rate eventually reached a maximum value, μmax, as the microorganisms became _____________ with the substrate

Answer 7

saturated

Question 8

This equation describes this
relationship between nutrient availability and growth rate.

Answer 8

Monod equation

Question 9

The rate of cell growth is influenced by

Answer 9

• temperature,
• pH,
• composition of medium,
• rate of air supply,
• and other factors

Question 10

In the case that all other conditions are kept constant, the specific growth rate may be affected by the

Answer 10

concentration of a certain specific substrate
(the limiting substrate)

Question 11

The simplest empirical expression for the effect of the substrate concentration on the specific growth rate is this equation

Answer 11

Monod Equation

Question 12

In the case of microbial growth kinetics, the growth-limiting substrate might be either a _____________________ or any component present in the growth medium, provided the variation in the concentration of the same affects the specific growth rate of the cell.

Answer 12

carbon source or a nitrogen source

Question 13

These limitations stem from the simplifications inherent in the Monod equation, which assumes constant values for parameters like the ____________________ and the ___________________________.

Answer 13

maximum specific growth rate
half-saturation constant

Question 14

Enumerate the limitations of the Monod Model

Answer 14

• When S →∞, µ → µmax.
• μ is finite when S is finite.
• Does not explain what will happen when S → 0.
• Does not take care of cell death.
• Not applicable in the case of substrate and product inhibitions.

Question 15

The alternative models consider additional factors, such as:

Answer 15

• microbial competition
• inhibitory effects, and
• dynamic changes in growth parameters

Question 16

Enumerate the other forms of growth kinetics

Answer 16

• Blackman Equation
• Tessier Equation
• Moser Equation
• Contois Equation

Question 17

The Blackman model was introduced in _______.

Answer 17

1905

Question 18

Assumption of the Blackman Model

Answer 18

• At a low substrate concentration, the rate of the uptake is proportional to the given substrate concentration.
• At a high substrate concentration both uptake and growth rates are independent of the given
  substrate concentration because some other substrates are limiting or microbial growth
  limiting factors are present.

Question 19

Just like the Monod model, at a low given substrate concentration, Blackman modelled the microbial per capita growth using the _________ kinetic model and at high substrate concentration, he modelled it using the ___________ kinetic model.

Answer 19

first-order
zero-order

Question 20

Blackman model is a piecewise function that makes a sharp switch from a _____________ to a _______________ when substrate concentration exceeds the concentration that supports half-maximum specific growth rate.

Answer 20

first-order to a zero-order

Question 21

Blackman’s model is a piecewise function that is ________________.

Answer 21

not continuous

Question 22

What is the Blackman’s piecewise function?

Answer 22

𝜇𝑔 =
𝜇𝑚𝑎𝑥𝑆/𝐾𝑆, 𝑆 < 𝐾𝑠
𝜇𝑚𝑎𝑥, 𝑆 ≥ 𝐾𝑠

Question 23

Like the Monod model, the Blackman model is unable to capture the___________ as well as
the ____________. Thus, as with the Monod model, the Blackman model is bound to __________________ during the lag and death phases.

Answer 23

lag phase
death phase

overestimate microbial growth

Question 24

Unlike the Monod model, this model saturates rapidly and thus may avoid underestimating the per capita growth rate around the neighborhood of the point where the transition occurs.

Answer 24

Blackman model

Question 25

The **conditions** under which the Blackman model is applicable are like those listed under the Monod mode:

Answer 25

1. ecosystems with **no adverse conditions** (perfect temperature) 2. ecosystems in which at **high substrate concentration**, *microbial growth* and *death rates* are **equal**. 3. ecosystems with **no substrate inhibition** or **toxic substrates** 4. ecosystems with **mature microbes** that are accustomed to them and their substrates

Question 26

The Teissier model was introduced in ______.

Answer 26

1942

Question 27

This model assumes that the dependence of the per capita growth rate 𝜇𝑔 on the limiting substrate (𝜇𝑔/𝑑𝑆) is **proportional** to the difference between the **per capita growth rate** and the **maximum** growth rate of microbes. Note: per capita (individual) growth rate means that it is 𝜇𝑔 Ineexplain lang dito yung equation!

Answer 27

Tessier Model 𝜇𝑔/𝑑𝑆 =1/𝐾𝑆(𝜇𝑚𝑎𝑥 − 𝜇g)

Question 28

Other term for Tessier model

Answer 28

Exponential specific growth rate model

Question 29

At the point where the transition from ____ substrate concentration dynamics to ______ substrate concentration dynamics occurs, the _______ kinetics will lie in between those predicted by the Monod and Blackman.

Answer 29

low high Tessier

Question 30

Thus, the ____________________always lies in between the Blackman and Monod curves

Answer 30

Tessier growth curve

Question 31

Just like the Monod model, Blackman model, and Moser models, the Teissier model is not capable of describing _______________. Hence it is not capable of describing the lag and death phase.

Answer 31

cell growth inhibition

Question 32

Who proposed Moser's model?

Answer 32

Herman Moser

Question 33

As a derivation from the Monod model, Moser modified the Monod model by __________________, ________, to capture the effects of **adoption** of microbes to **stationary processes by mutation**.

Answer 33

adding a third parameter n > 1

Question 34

The Moser equation model provides a degree of flexibility in fitting data and can simulate interesting dynamics in a ________________.

Answer 34

continuous stirred tank reactor

Question 35

Like the Monod model, this model does not capture the _____ phase of microbial kinetics. For **large values of n**, the ______ phase may be approximately captured by this model.

Answer 35

death lag

Question 36

The Moser model is a better model as _____ can be fine-tuned to capture some complex dynamics that may not be perfectly captured with the Monod model.

Answer 36

′𝑛′

Question 37

Just like the Blackman model, and Contois model, the Moser model has **not been widely used** to describe ______________________. The Moser model does not consider ________________; hence it **cannot deal with toxic substrate**.

Answer 37

specific growth rate substrate inhibition

Question 38

However, if the ______ phase were negligible and the ______ phase **significant**, the Moser model will be preferable.

Answer 38

death lag

Question 39

Contois proposed the model following the results of his work after applying the Monod model to ______________________ on defined **mineral salt media** containing *ammonium* as a nitrogen source and *glucose* or *succinic acid* as carbon sources.

Answer 39

Aerobacter aerogenes

Question 40

Contois' work reveals that the specific growth rate of microbes **did not only depend** on the _________________ but also was **inversely proportional** to the ________________in the culture. Note: Remember the formula for Contois Equation

Answer 40

limiting nutrients quantity of microbes, X

Question 41

In the Contois model, the assumption is that ___________________ is inversely proportional to specific growth rate. Note: Remember the formula for Contois Equation

Answer 41

biomass concentration

Question 42

Just like the Monod model, Blackman model, and Teissier model, the Contois model cannot describe the lag and death phase. Hence it does not:

Answer 42

capture substrate inhibition.

Question 43

Compared the experimental and simulated data of _________ and batch fermentation by various growth kinetic models and the _______________ gave the best results among all the other models

Answer 43

fed-batch Contois model

Question 44

The different growth equations can be described by a single differential equation as follows:

Answer 44

𝑑𝑣/𝑑𝑆 = 𝐾𝑣^𝑎(1 − 𝑣)^b where v = 𝜇𝑔/𝜇𝑚𝑎x