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21 Φεβ 2013 (πριν από 4 χρόνια και 5 μήνες)

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1








Zhaolei,

PhD


College of Life Science


Shandong Normal University


E
-
mail: zhaolei@sdu.edu.cn

Fermentation Engineering


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How to study effectively?



Give You a “PPT”


P:
Preview


P:
Practice


T:
Taking notes

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What can we learn from this course?


Knowledge


Approach

?,
Attitude

?,
Team work

?,
Skills

4

Introduction


Concept of fermentation


History of fermentation


Types of fermentation
products

¾
Steps in industrial
fermentation




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The term
fermentation

is
derived from the Latin
verb
fervere
, to boil,
which describes the
appearance of the action
of yeast on extracts of
fruit or malted grain
during the production of
alcoholic beverages.

What is fermentation?


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Biochemist


Fermentation is an anaerobic process where
energy is produced without the participation of
oxygen or other inorganic electron acceptors.

(“
life without air
”)

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Microbiologist


Any process for the production
of a product by the mass culture of
microorganisms.

Definition of Fermentation


Fermentation

is the chemical transformation
of organic substances into simpler compounds
by the action of enzymes, which are produced
by microorganisms such as molds, yeasts, or
bacteria.


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Fermentation is a

Unique process with great potential



Environment friendly


Consume less energy


Easy to manage


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History of fermentation


Ethanol fermentation was one of the first
chemical reactions observed by humans. In
nature, various types of food "go bad" as a
result of bacterial action. Early in history,
humans discovered that this kind of change
could result in the formation of products that
were enjoyable to consume.

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Made the earliest
microscopes which
magnified up to 300X.


Discovered micro
-
organisms.

Pioneers in Microbiology

Anthony van Leeuwenhoek

(1632
-
1723)

Leenvenhoek

′ s microscopes

(1822
-
1895)

Louis Pasteur


Showed microbes caused
fermentation & spoilage


Disproved spontaneous
generation of microorganisms


Developed aseptic techniques

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15


1843
-
1910




Developed pure culture
methods.


Established a sequence
of experimental steps to
show that a specific m.o.
causes a particular disease

——
Koch’s Postulates


Robert Koch

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Single strain

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The Nobel Prize in Chemistry 1907

"for his biochemical researches
and


his discovery of
cell
-
free
fermentation"

Eduard

Buchner

1860
-
1917

Germany





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In 1897,
Buchner

ground up a group of cells
with sand until they were totally destroyed.
Then he extracted the liquid and added it to a
sugar solution. His assumption was that
fermentation could no longer occur since the
cells were dead. But he was amazed to discover
that the cell
-
free liquid did indeed cause
fermentation.


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Start from an ancient time


Large scale production


Early 20th century


beverage industry,


vinegar, baking yeast, citric and lactic acid


Late 20th century


development of


biotechnology from the antibiotic industrial

History of
Fermentation engineering

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Major Products of Industrial Microbiology



Industrial and agricultural products



Fermented Food and Food additives



Products for human and animal health


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The
product

can either be


The cell itself:
referred to as biomass
production.




A microorganism own metabolite:
referred to as a product from a natural or
genetically improved strain.

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Products from Microorganisms

vinegar

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Q: Why antibiotics , amino acid
and enzymes could be produced by
microbial fermentation ?


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Micro
-
organisms cause changes in
the foods which:


Extend the shelf life ( preservation )


Producing desirable taste and flavour


Improvement of nutritional value


Producing required physicochemical properties

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Types of microbial products


Primary metabolites


——

produce during growth stage


related to synthesis of microbial cells in the
growth phase


include amino acids, nucleotides, fermentation
end products, and enzymes

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Secondary metabolites


——
produce after growth stage


accumulate following active growth


have no direct relationship to synthesis of
cell material and natural growth


include antibiotics and mycotoxins

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Primary metabolite

Microorganism

Significance

Ethanol

Saccharomyces
cerevisiae

alcoholic beverages

Citric acid

Aspergillus niger

food industry

Acetone and

butanol

Clostridium
acetobutyricum


solvents

Lysine and

Glutamic acid

Corynebacterium
glutamacium


nutritional additive
and flavour enhancer

Xanthan gum

Xanthomonas
campestris

industrial

Secondary metabolite

Microorganism

Significance

Penicillin

Penicillium
chrysogenum

antibiotic

Streptomycin

Streptomyces
griseus


antibiotic

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Contents

P.M.

S.M

Growth
needed?

Yes


No

Species
specificity?

No

Yes

Production
stage

during active growth

after growth phase

Examples

amino acid, nucleotide,

polysaccharide,

vitamin

antibiotics,

toxin,

hormones, pigment

Produced steadily by cell regulations

differences

similarities

primary vs. secondary metabolites

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Steps in Industrial Fermentation


Screen the best producing strain


Prepare medium and sterilization


Optimize production condition


Downstream processing


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seed fermenter

shake flask

stock culture

raw materials

medium formulation

sterilization

recovery

purification

fermenter

air

products

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Outline of a fermentation process

Upstream processing

Downstream processing

Raw Materials

Production microorganism

Fermentation

Product purification

Product

Effluent waste

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FERMENTATION

Process Control

Fermentation engineering


UPSTREAM

PROCESSES


DOWNSTREAM

PROCESSES

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UPSTREAM PROCESSES

-

Producer microorganism

-

Inoculum

development

-

Media formulation

-

Sterilization

-

Fermentation Process

FERMENTATION

Process Control

Fermentation engineering

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The essential components of a fermentor


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DOWNSTREAM PROCESSES


-

product extraction, purification


& assay


-

waste treatment


-
by product recovery

FERMENTATION

Process Control

Fermentation engineering

The ratio of recovery to fermentation costs for



L
-
asparaginase: 3.0 ethanol: 0.16

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How are microorganisms cultivated?


Petri Dishes


Shake Flasks


Fermentor

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The Fermentation Process

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Industrial production of yeast cells

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Review Questions

1.
Cite the following scientists’ outstanding contributions
to the fermentation industry:


leenvenhoek

偡獴敵e

䭯捨

慮搠䉵捨湥d

2.
What is fermentation and what are the main
components of fermentation engineering?

3.

What are the
primary metabolites and the secondary
metabolites? Give the differences between them with
examples.