Transcript Specialized English

Fermentation Engineering
赵 蕾
Zhaolei, PhD
College of Life Science
Shandong Normal University
E-mail: [email protected]
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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
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Introduction
Concept of fermentation
History of fermentation
Types of fermentation
products
Steps in industrial
fermentation
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What is fermentation?
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.
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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.
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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.
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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Pioneers in Microbiology
Anthony van Leeuwenhoek
Made the earliest
microscopes which
magnified up to 300X.
Discovered microorganisms.
(1632-1723)
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Leenvenhoek ′ s microscopes
Louis Pasteur
Showed microbes caused
fermentation & spoilage
Disproved spontaneous
generation of microorganisms
Developed aseptic techniques
(1822-1895)
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Robert Koch
Developed pure culture
methods.
Established a sequence
of experimental steps to
show that a specific m.o.
causes a particular disease
——Koch’s Postulates
（1843-1910）
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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
Germany
1860-1917
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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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History of Fermentation engineering
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
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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
Aspergillus niger
alcoholic beverages
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
Citric acid
food industry
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similarities
differences
primary vs. secondary metabolites
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
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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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raw materials
stock culture
medium formulation
shake flask
sterilization
seed fermenter
fermenter
air
recovery
purification
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products
Outline of a fermentation process
Raw Materials
Production microorganism
Fermentation
Upstream processing
Downstream processing
Product purification
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Effluent waste
Product
Fermentation engineering
UPSTREAM
PROCESSES
FERMENTATION
Process Control
DOWNSTREAM
PROCESSES
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Fermentation engineering
UPSTREAM PROCESSES
- Producer microorganism
- Inoculum development
- Media formulation
- Sterilization
- Fermentation Process
FERMENTATION
Process Control
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The essential components of a fermentor
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Fermentation engineering
DOWNSTREAM PROCESSES
FERMENTATION
Process Control
- product extraction, purification
& assay
- waste treatment
-by product recovery
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、Pasteur、Koch and Buchner
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.
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