Transcript Foundations in Microbiology

Chapter 27
Applied and Industrial
Microbiology
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Applied Microbiology and
Biotechnology
• Applied microbiology – microbes are used to
treat wastewater and bioremediate damaged
environments
• Industrial microbiology – use of microbes in
making food, medical, manufacturing, and
agricultural products
• Biotechnology – uses microbes for practical
applications
• Fermentation – controlled culture of microbes
to produce desired organic compounds
2
Water and Wastewater Treatment
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Water purification
• In most cities, water is
treated in a stepwise process
before it is supplied to
consumers
• Impoundment in large,
protected reservoir – storage
and sedimentation; treated to
prevent overgrowth of
cyanobacteria
• Pumped to holding tanks for
further settling, aeration, and
filtration; chemical treatment
with a chlorine, ozone, or
peroxide disinfectant
Catch basin of water
Aeration, settling
Filtration
Pumped to
holding
tank
Sand
Charcoal
Chlorination
Storage
Tank of
treated water
Toconsumer
consumerthrough
through
To
domestic
water
pipes
domestic water pipes
3
Sewage Treatment
• Sewage – used wastewater containing chemicals, debris,
and microorganisms
• Typically requires 3 phases:
Primary Stage
Secondary Stage
Tertiary Stage
– Primary phase – removes
floating, bulky physical
Supernatant
Sludge
Raw
HO
sewage
digester
digester
objects
Solids
– Secondary phase –
Liquid
Filtered
Mixed
Aerated
residue
removes the organic matter
by biodegradation, natural
Filtered
bioremediation in a large
Skimming
Chlorination
digester forming sludge
Settled solids
, settling
Solid wastes
which is aerated by injection
Treated sewage
released into
and stirred
Disposal
Disposed or reclaimed
body of water
for anaerobic digester
– Tertiary phase – filtration,
disinfection, and removal of
4
chemical pollutants
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2
Sewage Treatment
• Anaerobic digesters:
turn sludge into a
secondary source of
energy
• After completing the
sewage treatment
process, the water is
gradually released
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(a)
© Sanitation Districts of Los Angeles County
5
(b)
© Sanitation Districts of Los Angeles County
Microorganisms and Food
• Microbes and humans compete for nutrients
in food
• The effects of microorganisms on food can be
– Beneficial
– Detrimental
– Neutral
6
Microbial Fermentations in Food
Products
Microbes, through fermentation, can impart desirable
aroma, flavor, or texture to foods (starter cultures)
• Bread – yeast leaven dough by giving off CO2
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Carole Ritchie @ USDA-NRCS PLANTS Database
•
•
•
•
•
Beer – fermentation of wort
Wine – fermentation of fruit juices
Vegetable products – sauerkraut, pickles
Vinegar – fermentation of plant juices
Milk and dairy products – cheeses, yogurt
7
Wine Making
© Kevin Schafer/Peter Arnold
(a)
(b)
8
Microbes in Milk
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© Kathy Park Talaro/Visuals Unlimited
(a)
(b)
9
Cheese Making
10
Microorganisms as Food
• Mass-produced yeasts, molds, algae, and
bacteria
• Single-celled protein and filamentous
mycoprotein added to animal feeds
11
Concept Check:
Which of the following is not a stage in
purification of drinking water?
A. Filtration
B. Chlorination
C. Activated Sludge
D. Sedimentation
Microbial Involvement in FoodBorne Diseases
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• Food poisoning –
diseases caused by
ingesting food
• 2 types:
– Food intoxication –
results from ingesting
exotoxins secreted from
bacterial cells growing in
food
– Food infection –
ingestion of whole
microbes that target the
intestine – salmonellosis,
shigellosis
Food Intoxication
Food Infection
Cell
Toxin
Cells
Ingestion
Improper cooking technique
Bacteria
multiply
in food
Ingestion
Target organs
Intestinal
infection
(a)
(b)
13
Bacterial Food Poisoning Agents
14
Prevention Measures for Food
Poisoning and Spoilage
• Prevent incorporation of microbes into food
– Aseptic technique
– Handwashing and proper hygiene
• Prevent survival or multiplication of microbes
in food
–
–
–
–
–
–
Heat – autoclaving, pasteurization, cooking
Cold – refrigeration, freezing
Radiation – UV, ionizing
Chemical preservatives – NaCl, organic acids
Dessication
Spraying of bacteriophages
15
Prevention Measures for Food
Poisoning and Spoilage
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Care in Harvesting,
r
Preparation
oC
Destruction of Microbes
Heat
Canning Pasteurization
100o
Cooking
oF
212o
Boiling point
Bacterial destruction occurs
if high temperatures are
maintained long enough
Body temperature
Radiation
Filtration
Prevention of Growth
Maintenance
temperature
62.8o
145o
40o
104o
37.7o
100o
37o
36.1o
97o
15o
59o
7.2o
45o
0o
Hot
Cold
freezing
98.6o
32o
Freezing
point
*Bacteria
multiply
rapidly
Bacteria
multiply
Bacteria
multiply
at a
reduced
rate
Bacterial growth inhibited
0o
Preservative
additives
Nitrogen
salts
*Under ideal conditions, bacteria can
divide every 20 minutes. At this rate,
bacterial numbers could increase from 1
to 2,097,152 within 7 hours.
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General Concepts in
Industrial Microbiology
• Bulk production of organic compounds such
as antibiotics, hormones, vitamins, acids,
solvents, and enzymes
• Many processes involving fermentation
17
Industrial Enzymes
18
The Industrial Process
• Mutant strains of bacteria and fungi that synthesize large
amounts of metabolic intermediates (metabolites)
– Primary metabolites & Secondary metabolites –
Substrate
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Synthesis of only primary
metabolites (Production
of essential biochemicals)
Synthesis of primary and secondary
metabolites (Synthesis of byproducts
nonessential to growth)
Log Number of Viable Cells
Stationary phase
Death
phase
Exponential
phase
Lag
phase
19
Time
The Industrial Process
• Primary metabolites – produced during major metabolic
pathways and are essential to microbe’s function (amino
acids, organic acids synthesized during logarithmic growth)
• Secondary metabolites – by-products of metabolism that
may not be critical to microbe’s function (vitamins, antibiotics,
and steroids synthesized during stationary phase)
Substrate
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Synthesis of only primary
metabolites (Production
of essential biochemicals)
Synthesis of primary and secondary
metabolites (Synthesis of byproducts
nonessential to growth)
Log Number of Viable Cells
Stationary phase
Death
phase
Exponential
phase
Lag
phase
20
Time
Tricks to Increase the Amount of
Chosen End Product
1. Manipulate growth environment to increase
synthesis of metabolite
2. Select strains that genetically lack a
feedback system
3. Many syntheses occur in sequential fashion
involving more than one organism
– Biotransformation – waste product of
one organism becomes the building block
of the next
21
Biotransformation
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C
CH3
Colletotrichum
antirrhini
CH3
C
O
C
CH3
d
O
CH3
Rhizopus
nigricans
CH3
OH
CH3
O
15α-hydroxyprogesterone
Progesterone
O
a
Δ4-pregnene-3,20-dione
CH3
C
b
Curvularia
lunata
C
O
CH3
H2COH
c
HO
O
O
CH3
CH3
Side
reaction
HO
CH3
c
O
11α-hydroxyprogesterone
Corticosterone
H2COH
C
O
CH3
Δ4-pregnene-11β,21-diol-3,20-dione
O
OH
O
CH3
H2COH
b
C
CH3
O
OH
Cortisone
C
O
CH3
b
O
b
O
CH3
Fusarium
solani
O
17β-hydroxy-11-dehydrocorticosterone
(cortisone)
H2COH
O
O
CH3
11-dehydrocortisone
22
From Microbial Factories to
Industrial Factories
• Produce appropriate
levels of growth and
fermentation in a
carefully controlled
environment
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Motor
Addition of
nutrient and
microbes
Cooling
water out
Sample
line
Valve
Impellers
• Commercial fermentation
carried out in fermentors
– a device in which mass
cultures are grown,
reactions take place, and
product develops
Temperature
sensor and
control unit
Cooling
jacket
Cooling
water in
Valve
Sparger
Air in
Valve
Harvest
line
Downstream processing
Air filter
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Substance Production
2.
3.
4.
•
Introduction of microbes
and sterile media into
reaction chamber
Fermentation
Downstream processing
(recovery, purification,
packaging)
Removal of waste
Carried out aseptically
and monitored for rate of
flow and quality of product
Introduction
of Reactants
1.
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Raw materials
Pretreatment
with enzymes
Growth of stock culture
for inoculum
Nutrients added
Medium sterilized
Fermentor
chamber
Fermentation
Steps in mass production:
pH
buffer
O2
Medium
collected
Downstream Processing
and Waste Removal
•
Recovery
of
raw product
Microbes
recovered
Filtration,
extraction
Purification,
drying
Packaging
Solids
collector
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Substance Production
• Batch fermentations – substrate added to
system all at once and taken through a limited
run until product is harvested
• Continuous feed systems – nutrients are
continuously fed into the reactor and product is
siphoned off throughout run
25
Examples of Industrial Products
• Pharmaceutical products
–
–
–
–
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Antibiotics
Hormones
Vitamins
Vaccines
• Miscellaneous products
–
–
–
–
–
–
Biopesticides
Enzymes
Amino acids
Organic acids
Solvents
Natural flavor compounds
26
Industrial Products
27
Concept Check:
The large tanks used in industrial production of
antibiotics are termed
A. Digesters
B. Fermentors
C. Spargers
D. Biotransformers