Quiz 3 - Pt. 2 (Solid state fermentation)

Question 1

• fermentations of solid materials
• low moisture levels
• smaller reactor volume
• low contamination and easy product separation
  ▪ Easy product separation
  ▪ Energy efficiency
  ▪ Differentiated microbiological
  structures

Answer 1

Solid-state Fermentations

Question 2

feed flows through a column packed with immobilized cells

Answer 2

Packed column

Question 3

feed flows up through a bed of immobilized cells, fluidizing the immobilized cell particles

Answer 3

Fluidized bed

Question 4

air bubbles suspend the immobilized cell particles in a reactor

Answer 4

Airlift

Question 5

• multilayer growth of cells on solid support
• common in waste water treatment
  ▪ Support materials can be biologically active or inert

Answer 5

Biological films

Question 6

_____ is widely used for enzymes but not for cells

In general, good ______ should be rigid and chemically inert, should bind cells firmly, high loading capacity

Answer 6

Covalent binding
good support materials

Question 7

there is direct contact between nutrient and support materials; high cell loading

Answer 7

Physical adsorption

Question 8

• animal cell culture
• cell retention and selective removal of dead cells
• removal of cell debris and inhibitory by-products
• high medium use, costs raw materials and sterilization

Answer 8

Perfusion culture

Question 8

________ provide cofactors, reducing power, energy that many enzymatic reactions require

Answer 8

Whole cells

Question 9

Physical Adsorption

selection of suitable support materials is highly based on ______ and _________

Answer 9

adsorption capacity;
strength of binding

Question 10

methods of preparing polymer beads for Physical Entrapment

Answer 10

1) Gelation of polymers
2) Precipitation of polymers
3) Ion exchange gelation
4) Polycondensation
5) Polymerization

Question 11

_____ most widely used method of cell entrapment

▪ Various matrices: porous polymers
(agar, alginate, carrageenan, polyacrylamide, chitosan, gelatin, collagen)
▪ Porous metal screens
▪ Polyurethane
▪ Silica gel
▪ Polystyrene
▪ Cellulose triacetate
* polymer beads

Answer 11

Physical entrapment

Question 12

similar to enzyme immobilization; entrapment and binding

Answer 12

Active immobilization

Question 13

uses biofilm

Answer 13

Passive immobilization

Question 14

multi-layer growth on solid surfaces

Answer 14

Biofilm

Question 15

• high cell concentrations
• eliminates cell washout at high dilution rates
• high volumetric productivities
• May provide favorable microenvironment
  ▪ Genetic stability
  ▪ Protection from shear damage
• Major Limitation: Mass transfer (_____) resistances

Answer 15

Immobilized cell system
diffusional

Question 16

taken through many feeding cycles, with each feeding cycle followed by a harvest cycle during which the volume is drawn back down to V0 and the cycle begins again

Answer 16

Repeated fed-batch

Question 17

Fed-batch Operation

are started as batch cultures and grown to an initial cell concentration X

Answer 17

Fed-batch cultures

Question 18

Fed-batch Operation

• gain some advantages of a CSTR, retain some disadvantages of batch
• ____reduces substrate inhibition or catabolic repression
• ____ nature usually leads to higher operations cost and batch variability

Answer 18

Fed-batch reactors
Semi-batch nature

Question 19

Multistage chemostat

First ________ is fed with a non-inducing growth substrate, allowing the recombinant strain to be produced

the _____ from the first chemostat feeds a second chemostat that is _______, and the product is produced.

Answer 19

Chemostat
Effluent
Fed inducer

Question 20

Special Cases - Chemostat

________ and wild type grow at the same rate if the recombinant product is not expressed

Answer 20

Recombinant strain

Question 21

Special Cases - Chemostat

if the recombinant product is expressed, the recombinant strain grows much ________

Answer 21

Slower

Question 22

are continually added to the second chemostat not allowing take-over by a fast growing mutant

Answer 22

New recombinant cells

Question 23

chemostats cannot be operated if ______

Answer 23

Umax < D (dilution rate)

Question 24

What is desired if we have a **high volume of feed** with a **low concentration** of substrate?

Answer 24

High dilution rate

Question 25

- is more **mechanically reliable** and more **flexible** - equations were for cell mass

Answer 25

Batch reactor

Question 26

maintaining the organism with the **desired characteristics**

Answer 26

Genetic stability

Question 27

maintaining a **sterile system**

Answer 27

Operability

Question 28

**validating the process**; initially, many process batch is too expensive to revalidate after clinical trials

Answer 28

Regulatory

Question 29

**rate of product per time per volume**. Chemostat better for growth associated products. Wasted time in batch process.

Answer 29

Productivity

Question 30

**ability to make more than one** product with the same reactor. Batch better.

Answer 30

Flexibility

Question 31

**maintaining the same conditions for all of the product** produced. In theory, chemostat better, steady state.

Answer 31

Control

Question 32

**Specialized** Reactors

Answer 32

▪ Chemostat with recycle ▪ Multistage chemostat ▪ Fed-batch ▪ Perfusion

Question 33

▪ Recombinant product under the control of an **inducible promoter.**

Answer 33

Special Cases - Chemostat

Question 34

types of immobilization

Answer 34

active immobilization passive immobilization

Question 35

porous support materials causes **intraparticle pore diffusion** (at high cell densities) and **hard to control** microenvironmental conditions

Answer 35

Disadvantage of Physical Entrapment

Question 36

▪ Analysis similar to immobilized enzymes ▪ Damkohler number ▪ Effectiveness factor ▪ Thiele modulus

Answer 36

Diffusional Limitations of bilogical films

Question 37

**3 Immobilized Bioreactors**

Answer 37

▪ Packed-column ▪ Fluidized-bed ▪ Airlift