Lesson 3: Stoich of Microbial Growth & Product Formation

Question 1

represent the stoichiometry of conversion of substrates into products and cellular materials

Answer 1

pseudochemical equations

Question 2

_________ and __________ are complex processes reflecting the overall kinetics and stoichiometry of the thousands of intracellular reactions that can be observed within a cell

Answer 2

Cell growth
product formation

Question 3

pseudochemical equations will

Answer 3

represent the stoichiometry of conversion of substrates into products and cellular materials

Question 4

gen equation

Answer 4

substrate + O2 + NH3 = biomass + product + H20 +CO2

Question 4

For many process calculations, it is desired to compare potential substrates in terms of ______, or _______, or ____________

Answer 4

cell mass yield,
product yield,
evolution of heat

Question 4

There may also be a need to know how close to its ___________ a system is operating

Answer 4

thermodynamic limit

Question 5

usually constrained by kinetic or thermodynamic considerations?

Answer 5

product yield

Question 6

If a system is close to its thermodynamic limit, it would be unwise to try to improve production through _______ or _________.

Answer 6

mutation or genetic engineering

Question 6

product yield constrained by either _______ or _______

Answer 6

kinetic or thermodynamic considerations

Question 6

T/F: If a system is close to its thermodynamic limit, it would be wise to try to improve production through mutation or genetic engineering.

Answer 6

F: it is unwise

Question 6

the maximum yield of cell mass per unit mass of substrate consumed when no maintenance is considered

Answer 6

Overall growth yield coefficient,
𝒀M_𝑿/𝑺

Question 6

the amount of biomass synthesized per mole of ATP generated

Answer 6

ATP yield coefficient,
𝒀M_𝑿/𝑨𝑻𝑷

Question 7

yield coefficient based on oxygen consumption

Answer 7

Oxygen yield coefficient,
𝒀M_𝑿/𝑶𝟐

Question 7

Observed to be nearly constant at 10 to 11 grams dry
weight per mole ATP for heterotrophic growth of many
substrates and organisms under anaerobic conditions

Answer 7

ATP yield coefficient,
𝒀M_𝑿/𝑨𝑻𝑷ATP yield coefficient,
𝒀M_𝑿/𝑨𝑻𝑷

Question 8

ATP yield coefficient is Observed to be nearly constant at _____-____ grams dry weight per mole ATP for heterotrophic growth of many
substrates and organisms under anaerobic conditions

Answer 8

10 to 11

Question 8

are autotrophic organisms

Answer 8

𝐶𝑂2 fixers

Question 8

ATP yield coefficient is Observed to be nearly constant at _____-____ _______ for heterotrophic growth of many substrates and organisms under anaerobic conditions

Answer 8

10-11 grams dry weight per mole ATP

Question 8

ATP yield coefficient is usually >10.5 𝐠/ 𝐦𝐨𝐥 𝐀𝐓𝐏 for organisms under _____ ___

Answer 8

aerobic conditions

Question 8

ATP yield coefficient is Observed to be nearly constant at _____-____ grams dry weight per mole ATP for _____ ___ of many substrates and organisms under ______ ___

Answer 8

10-11
heterotrophic growth
anaerobic conditions

Question 8

ATP yield coefficient for many autotrophic organisms (𝐶𝑂2 fixers)

Answer 8

≈ 𝟔. 𝟓 𝐠/ 𝐦𝐨𝐥 𝐀𝐓𝐏

Question 9

ATP yield coefficient is Usually _______ if under aerobic conditions

Answer 9

> 10.5 𝐠/ 𝐦𝐨𝐥 𝐀𝐓𝐏

Question 9

ATP yield coefficient is approx 6.5 𝐠/ 𝐦𝐨𝐥 𝐀𝐓𝐏 for many _____ ___

Answer 9

autotrophic organisms

Question 9

chemostat

Answer 9

CSTR

Question 9

CSTR

Answer 9

continuous stirred tank reactor

Question 9

has highest M_𝑨𝑻𝑷 anaerobic organism in a chemostat, with what growth limiting factor

Answer 9

E. aerogenes [38.7] Tryptophan

Question 9

has lowest M_𝑨𝑻𝑷 anaerobic organism in a chemostat, with what growth limiting factor

Answer 9

C. parapsilosis [0.2], glucose C. acetobutylicum [-], glucose

Question 9

has highest 𝒀M_𝑿/𝑨𝑻𝑷 anaerobic organism in a chemostat, with what growth limiting factor

Answer 9

E. aerogenes [25.4] Tryptophan

Question 9

has lowest 𝒀M_𝑿/𝑨𝑻𝑷 anaerobic organism in a chemostat, with what growth limiting factor

Answer 9

E. coli [8.5], - E. aerogenes [9.0], Citrate

Question 9

lowest to highest M_𝑨𝑻𝑷 anaerobic organism in a chemostat

Answer 9

[------] C. acetobutylicum [0.20] C. parapsilosis [0.25] S. cerevisiae [ - ] [0.50] S. cerevisiae [glucose] [0.07] S. cerevisiae (petite) [1.50] L. casei [2.20] E. aerogenes [citrate] [2.30] E. aerogenes [glucose, b] [2.30] S. cremoris [6.80] E. aerogenes [glucose, a] [6.90] E. coli [glucose] [18.9] E. coli [-] [38.7] E. aerogenes [tryptophan]

Question 9

lowest to highest 𝒀M_𝑿/𝑨𝑻𝑷 anaerobic organism in a chemostat

Answer 9

[08.5] E. coli [-] [09.0] E. aerogenes [citrate] [10.3] E. coli [glucose] [11.0] S. cerevisiae [glucose] [11.3] S. cerevisiae (petite) [12.5] C. parapsilosis [12.6] S. cremoris [13.0] S. cerevisiae [ - ] [14.0] E. aerogenes [glucose, a] [17.6] E. aerogenes [glucose, b] [23.8] C. acetobutylicum [24.3] L. casei [25.4] E. aerogenes [tryptophan]

Question 10

E. aerogenes has _____ 𝒀M_𝑿/𝑨𝑻𝑷 in complex medium than minimal medium

Answer 10

greater [a=14.0, b=17.6]

Question 10

E. aerogenes has _____ M_𝑨𝑻𝑷 in complex medium than minimal medium

Answer 10

lower [a=6.7, b=2.3]

Question 10

Using E. aerogenes, what growth limiting factor yeilds the highest and lowest M_𝑨𝑻𝑷 and 𝒀M_𝑿/𝑨𝑻𝑷

Answer 10

highest M_𝑨𝑻𝑷: tryptophan [37.7] highest 𝒀M_𝑿/𝑨𝑻𝑷: tryptophan [25.4] highest M_𝑨𝑻𝑷: citrate [2.2] highest 𝒀M_𝑿/𝑨𝑻𝑷: citrate [9.0]

Question 10

highest to lowest ATP yield growth medium [5]

Answer 10

[31.9] G+AA+NA [28.8] G+IS [21.0] Pyruvate+AA+NA [13.5] Pyruvate+IS [6.50] CO2+IS (autotroph)

Question 10

reciprocal of residence time, a function of flowrate and culture volume

Answer 10

dilution rate

Question 10

can also be estimated using an equation analogous to the one developed for substrate yield coefficient in a chemostat

Answer 10

maintenance coefficient 1/YAP_X/ATP = 1/YM_X/ATP + M_ATP/D

Question 10

As indicated in Table 6.1, values of 𝒀𝑿/𝑶𝟐 can vary from 0.17 to 1.5 g biomass/g 𝑂2, depending on _____ and ____.

Answer 10

substrate organism

Question 10

As indicated in Table 6.1, values of 𝒀𝑿/𝑶𝟐 can vary from ____ to _____ biomass/g 𝑂2, depending on substrate and organism.

Answer 10

0.17 to 1.5 g

Question 10

a particularly important derived parameter

Answer 10

Respiratory Quotient (RQ)

Question 10

... defined as moles of 𝑪𝑶𝟐 produced per mole of oxygen consumed

Answer 10

Respiratory Quotient (RQ)

Question 10

...provides an indication of metabolic state (ex. aerobic growth versus ethanol fermentation in baker’s yeast)

Answer 10

Respiratory Quotient (RQ)

Question 10

...can be used in process control

Answer 10

Respiratory Quotient (RQ)

Question 10

ratio of phosphate bonds formed per unit of oxygen consumed

Answer 10

P/O Ratio

Question 11

indicates the efficiency of conversion of reducing power into high-energy phosphate bonds in the respiratory chain

Answer 11

P/O Ratio

Question 11

is ~3 for eucaryotes when glucose is the substrate

Answer 11

P/O Ratio

Question 11

is significantly less in procaryotes

Answer 11

P/O Ratio

Question 11

P/O Ratio (value) for eucaryotes when glucose is the substrate

Answer 11

approx 3

Question 11

the number of 𝐻+ ions released per unit of oxygen consumed

Answer 11

H/O Ratio

Question 11

Electron generation is directly related to proton release.

Answer 11

H/O Ratio

Question 11

Usually 4 mol of electrons are consumed per mole of oxygen consumed.

Answer 11

H/O Ratio

Question 11

The generation of electrons results in the expulsion of 𝐻+ that can be used directly to drive the transport of some substrates or to generate ATP.

Answer 11

H/O Ratio

Question 11

number of mol of electrons are consumed per mole of oxygen consumed.

Answer 11

4, H/O ratio

Question 11

refers to parameters are nearly the same irrespective of the species or substrate involved.

Answer 11

regularities

Question 11

T/F: The complexity of mass and energy balances for cellular growth can be decreased greatly through the recognition that some parameters are nearly the same irrespective of the species or substrate involved.

Answer 11

T

Question 11

Three important regularities were first identified first by [2]

Answer 11

I. G. Minkevich V. K. Eroshin

Question 11

_____ equivalent of available electrons transferred to oxygen (coefficient of variation of 4%)

Answer 11

26.95 kcal/g

Question 11

______ equivalent of available electrons per quantity of biomass containing 1 g atom carbon

Answer 11

4.291 g

Question 11

_____ carbon in biomass per gram of dry biomass

Answer 11

0.462 g

Question 11

𝑌𝑋/𝑒− = ______ ± 0.11 g dry wt/g equivalent of electrons.

Answer 11

3.14

Question 11

T/F: observed average values of cell composition and yields facilitate estimates of other growth-related parameters.

Answer 11

T

Question 11

A ___ ___ on biological reactions can easily be written when the compositions of substrates, products, and cellular material are known.

Answer 11

material balance

Question 11

Usually, _____ ___ are required in addition to elemental balances to determine the stoichiometric coefficients in bioreactions.

Answer 11

electron–proton balances

Question 11

T/F: Accurate determination of the composition of cellular material is a major problem.

Answer 11

T

Question 11

defined as the amount containing 1 gram atom of carbon, such as 𝐂𝐇𝜶𝐎𝜷𝐍𝜸

Answer 11

One mole of biological material

Question 11

represents 1 mole of carbohydrate

Answer 11

CH𝑚𝑂𝑛 [substrate?]

Question 11

stands for 1 mole of cellular material

Answer 11

CH𝛼O𝛽N𝛾 [biomass?]

Question 12

ratio CO2/O2

Answer 12

RQ [respiratory quotient]

Question 12

T/F: In more complex reactions, as in the formation of extracellular products, an additional stoichiometric coefficient is added, requiring more information.

Answer 12

T

Question 13

T/F: Elemental balances provide no insight into the energetics of a reaction.

Answer 13

T

Question 14

ThIS concept has been developed and used for proton–electron balances in bioreactions.

Answer 14

degree of reduction [𝜸]

Question 14

defined (for organic compounds) as the number of equivalents of available electrons* per gram atom C

Answer 14

degree of reduction [𝜸]

Question 14

values for some key elements [CHONPS]

Answer 14

C = 4 H = 1 O = -2 N = -3 S = 6 P = 5

Question 15

those that would be transferred to oxygen upon oxidation of a compound to CO2, H2O, and NH3

Answer 15

available electrons

Question 15

high degree of reduction indicates _____ _ ____

Answer 15

low deg of oxidation

Question 16

deg of deduction of C6H12O6

Answer 16

𝜸 = [6(4) + 12(1)+ 6(-2)]/[6] 𝜸 = 4

Question 17

consider rxn eqn for aerobic production of a single extracellular product, what compound have a deg of reduction of zero [3]

Answer 17

CO2 H2O NH3

Question 17

Y_X/S and Y_P/S should be in ____ basis

Answer 17

molar

Question 17

consider for aerobic production of a single extracellular product, what are the deg of reduction CO2, H2O and NH3

Answer 17

zero

Question 18

From electron balance, an energy balance, and a total mass balance, only _____ variables will be independent

Answer 18

five [chons?or..]

Question 19

ATP yield in many anaerobic fermentation is approx

Answer 19

10.5 ± 2gdw cells/ mol ATP

Question 19

ATP yield for aerobic fermentation varies between ....

Answer 19

6-29

Question 20

energy yield of metabolic pathway

Answer 20

N

Question 21

it is defined as the mols of ATP produced per gram of substrate consumed

Answer 21

energy yield of metabolic pathway, N

Question 22

Y_X/ATP * N is equal to

Answer 22

Y_X/S (g product/g substrate)

Question 23

T/F: The prediction of yield coefficients is not exact, because unknown/ unaccounted for metabolic pathways and products are present, but such calculations provide useful first estimates of such parameters.

Answer 23

T